Patent ID: 12239533

DETAILED DESCRIPTION OF THE INVENTION

Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structures. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.

FIG.1shows an example embodiment of a catheter-based delivery system in accordance with aspects of the invention. The delivery system utilizes a pair of magnetic catheters that are advanced from separate vascular access points and magnetically coupled across a tissue within the heart. The pair of catheters include a great cardiac vein (GCV) anchor delivery catheter50which is introduced from the jugular vein and advanced along a superior vena cava (SVC) approach to the GCV, and a left atrial (LA) catheter60, which is introduced at the femoral vein and introduced along an inferior vena cava (IVC) approach, across the inter-atrial septum and into the left atrium. Each catheter includes a magnetic head along a distal portion thereof (magnetic head52of catheter50and magnetic head62of catheter60) such that when magnetically coupled, the catheters provide a stable region to facilitate penetration of a tissue wall between the LA and GCV and subsequent advancement of the puncturing guidewire54through the GCV catheter50and into the LA catheter60. Notably, a trailing end of the puncturing guidewire54is attached to one end of a bridging element12(for example, suture), the other end of which is attached to posterior anchor18disposed on the distal portion of GCV catheter50. Such a configuration allows the bridging element12to be advanced across the left atrium by advancing the puncturing guidewire54through the LA catheter60to exit from the femoral vein, while the magnetic heads remain magnetically coupled to each other, as shown inFIG.13. As can be understood by referring toFIG.13, the penetrating guidewire54has a length greater than the combined length of the catheters such that the guidewire54can be manually advanced externally from one vascular access point until the guidewire54exits the other vascular access point due to the stiffness of the guidewire54. The guidewire54can be further retracted after exiting so as to pull the attached bridging element through the vascular path until the bridging element also exits the same vascular access point. Performing this process while the GCV catheter50and LA catheter60are magnetically coupled provides improved stability during the process and, more importantly, covers the puncturing guidewire54and bridging element12while being pulled across the delicate tissues of the heart. The benefits of such a configuration, as compared to conventional delivery approaches, include improved safety for the patient, single operator deployment, significantly reduced duration of the deployment procedure and reduced delivery device lengths and cost of goods. The advantages of such an approach in deploying the implant can be understood further by referred to the following figures, which describe the implant and associated components in more detail as well as conventional approaches of delivery and deploying such implants.

Heart Implants for Treatment/Repair of a Heart Valve Annulus

Implant Structure

FIGS.3A-3Bshow embodiments of an implant10that is sized and configured to extend across the left atrium in generally an anterior-to-posterior direction, spanning the mitral valve annulus. The implant10comprises a spanning region or bridging element12having a posterior anchor region14and an anterior anchor region16.

The posterior anchor region14is sized and configured to allow the bridging element12to be placed in a region of atrial tissue above the posterior mitral valve annulus. This region is preferred, because it generally presents more tissue mass for obtaining purchase of the posterior anchor region14than in a tissue region at or adjacent to the posterior mitral annulus. Engagement of tissue at this supra-annular location also may reduce risk of injury to the circumflex coronary artery. In a small percentage of cases, the circumflex coronary artery may pass over and medial to the great cardiac vein on the left atrial aspect of the great cardiac vein, coming to lie between the great cardiac vein and endocardium of the left atrium. However, since the forces in the posterior anchor region are directed upward and inward relative to the left atrium and not in a constricting manner along the long axis of the great cardiac vein, the likelihood of circumflex artery compression is less compared to other technologies in this field that do constrict the tissue of the great cardiac vein. Nevertheless, should a coronary angiography reveal circumflex artery stenosis, the symmetrically shaped posterior anchor may be replaced by an asymmetrically shaped anchor, such as where one limb of a T-shaped member is shorter than the other, thus avoiding compression of the crossing point of the circumflex artery. The asymmetric form may also be selected first based on a pre-placement angiogram.

An asymmetric posterior anchor may be utilized for other reasons as well. The asymmetric posterior anchor may be selected where a patient is found to have a severely stenotic distal great cardiac vein, where the asymmetric anchor better serves to avoid obstruction of that vessel. In addition, an asymmetric anchor may be chosen for its use in selecting application of forces differentially and preferentially on different points along the posterior mitral annulus to optimize treatment, for example, in cases of malformed or asymmetrical mitral valves.

The anterior anchor region16is sized and configured to allow the bridging element12to be placed, upon passing into the right atrium through the septum, adjacent tissue in or near the right atrium. For example, as is shown inFIGS.3A-3B, the anterior anchor region16may be adjacent or abutting a region of fibrous tissue in the interatrial septum. As shown, the anchor site16is desirably superior to the anterior mitral annulus at about the same elevation or higher than the elevation of the posterior anchor region14. In the illustrated embodiment, the anterior anchor region16is adjacent to or near the inferior rim of the fossa ovalis. Alternatively, the anterior anchor region16can be located at a more superior position in the septum, for example, at or near the superior rim of the fossa ovalis. The anterior anchor region16can also be located in a more superior or inferior position in the septum, away from the fossa ovalis, provided that the anchor site does not harm the tissue in the region.

Alternatively, the anterior anchor region16, upon passing through the septum into the right atrium, may be positioned within or otherwise extend to one or more additional anchors situated in surrounding tissues or along surrounding areas, such as within the superior vena cava (SVC) or the inferior vena cava (IVC).

In use, the spanning region or bridging element12can be placed into tension between the two anchor regions14and16. The implant10thereby serves to apply a direct mechanical force generally in a posterior to anterior direction across the left atrium. The direct mechanical force can serve to shorten the minor axis (along line P-A inFIG.2E) of the annulus. In doing so, the implant10can also reactively reshape the annulus along its major axis (line CM-CL inFIG.2E) and/or reactively reshape other surrounding anatomic structures. It should be appreciated, however, the presence of the implant10can serve to stabilize tissue adjacent the heart valve annulus, without affecting the length of the minor or major axes.

It should also be appreciated that, when situated in other valve structures, the axes affected may not be the “major” and “minor” axes, due to the surrounding anatomy. In addition, in order to be therapeutic, the implant10may only need to reshape the annulus during a portion of the heart cycle, such as during late diastole and early systole when the heart is most full of blood at the onset of ventricular systolic contraction, when most of the mitral valve leakage occurs. For example, the implant10may be sized to restrict outward displacement of the annulus during late ventricular diastolic relaxation as the annulus dilates.

The mechanical force applied by the implant10across the left atrium can restore to the heart valve annulus and leaflets a more normal anatomic shape and tension. The more normal anatomic shape and tension are conducive to coaptation of the leaflets during late ventricular diastole and early ventricular systole, which, in turn, reduces mitral regurgitation.

In its most basic form, the implant10is made from a biocompatible metallic or polymer material, or a metallic or polymer material that is suitably coated, impregnated, or otherwise treated with a material to impart biocompatibility, or a combination of such materials. The material is also desirably radiopaque or incorporates radiopaque features to facilitate fluoroscopic visualization.

In some embodiments, the implant10, or at least a portion thereof, can be formed by bending, shaping, joining, machining, molding, or extrusion of a metallic or polymer wire form structure, which can have flexible or rigid, or inelastic or elastic mechanical properties, or combinations thereof. In other embodiments, the implant10, or at least a portion thereof, can be formed from metallic or polymer thread-like or suture material. Materials from which the implant10can be formed include, but are not limited to, stainless steel, Nitinol, titanium, silicone, plated metals, Elgiloy™, NP55, and NP57.

In any of the implants described herein, the bridging member can be formed of a substantially inelastic material, such as a thread-like or suture material.

The Posterior Anchor Region

The posterior anchor region14is sized and configured to be located within or at the left atrium at a supra-annular position, for example, positioned within or near the left atrium wall above the posterior mitral annulus.

In the illustrated embodiment, the posterior anchor region14is shown to be located generally at the level of the great cardiac vein, which travels adjacent to and parallel to the majority of the posterior mitral valve annulus. This extension of the coronary sinus can provide a strong and reliable fluoroscopic landmark when a radiopaque device is placed within it or contrast dye is injected into it. As previously described, securing the bridging element12at this supra-annular location also lessens the risk of encroachment of and risk of injury to the circumflex coronary artery compared to procedures applied to the mitral annulus directly. Furthermore, the supra-annular position assures no contact with the valve leaflets therefore allowing for coaptation and reduces the risk of mechanical damage.

The great cardiac vein also provides a site where relatively thin, non-fibrous atrial tissue can be readily augmented and consolidated. To enhance hold or purchase of the posterior anchor region14in what is essentially non-fibrous heart tissue, and to improve distribution of the forces applied by the implant10, the posterior anchor region14may include a posterior anchor18placed within the great cardiac vein and abutting venous tissue. This makes possible the securing of the posterior anchor region14in a non-fibrous portion of the heart in a manner that can nevertheless sustain appreciable hold or purchase on that tissue for a substantial period of time, without dehiscence, expressed in a clinically relevant timeframe.

The Anterior Anchor Region

The anterior anchor region is sized and configured to allow the bridging element12to remain firmly in position adjacent or near the fibrous tissue and the surrounding tissues in the right atrium side of the atrial septum. The fibrous tissue in this region provides superior mechanical strength and integrity compared with muscle and can better resist a device pulling through. The septum is the most fibrous tissue structure in its own extent in the heart.

Surgically handled, it is usually one of the only heart tissues into which sutures actually can be placed and can be expected to hold without pledgets or deep grasps into muscle tissue, where the latter are required.

As shown inFIGS.3A-3B, the anterior anchor region16passes through the septal wall at a supra-annular location above the plane of the anterior mitral valve annulus. The supra-annular distance on the anterior side can be generally at or above the supra-annular distance on the posterior side. The anterior anchor region16is shown at or near the inferior rim of the fossa ovalis, although other more inferior or more superior sites can be used within or outside the fossa ovalis, taking into account the need to prevent harm to the septal tissue and surrounding structures.

By locating the bridging element12at this supra-annular level within the right atrium, which is fully outside the left atrium and spaced well above the anterior mitral annulus, the implant10avoids the impracticalities of endovascular attachment at or adjacent to the anterior mitral annulus, where there is just a very thin rim of annulus tissue that is bounded anteriorly by the anterior leaflet, inferiorly by the aortic outflow tract, and medially by the atrioventricular node of the conduction system. The anterior mitral annulus is where the non-coronary leaflet of the aortic valve attaches to the mitral annulus through the central fibrous body. Anterior location of the implant10in the supra-annular level within the right atrium (either in the septum or in a vena cava) avoids encroachment of and risk of injury to both the aortic valve and the AV node.

The purchase of the anterior anchor region16in fibrous septal tissue is desirably enhanced by a septal member30or an anterior anchor20, or a combination of both.FIGS.3A and3Bshow the anterior anchor region including a septal member30. The septal member30may be an expandable device and also may be a commercially available device such as a septal occluder, for example, Amplatzer® PFO Occluder (seeFIGS.5A-5B). The septal member30preferably mechanically amplifies the hold or purchase of the anterior anchor region16in the fibrous tissue site. The septal member30also desirably increases reliance, at least partly, on neighboring anatomic structures of the septum to make firm the position of the implant10. In addition, the septal member30may also serve to plug or occlude the small aperture that was created in the fossa ovalis or surrounding area during the implantation procedure.

Anticipating that pinpoint pulling forces will be applied by the anterior anchor region16to the septum, the forces acting on the septal member30should be spread over a moderate area, without causing impingement on valve, vessels or conduction tissues. With the pulling or tensioning forces being transmitted down to the annulus, shortening of the minor axis is achieved. A flexurally stiff septal member is preferred because it will tend to cause less focal narrowing in the direction of bridge element tension of the left atrium as tension on the bridging element is increased. The septal member30should also have a low profile configuration and highly washable surfaces to diminish thrombus formation for devices deployed inside the heart. The septal member may also have a collapsed configuration and a deployed configuration. The septal member30may also include a hub31(seeFIGS.5A and5B) to allow attachment of the anchor20. A septal brace may also be used in combination with the septal member30and anterior anchor20to distribute forces uniformly along the septum. Alternatively, devices in the IVC or the SVC can be used as anchor sites, instead of confined to the septum.

Location of the posterior and anterior anchor regions14and16having radiopaque bridge locks and well demarcated fluoroscopic landmarks respectively at the supra-annular tissue sites just described, not only provides freedom from key vital structure damage or local impingement, for example, to the circumflex artery, AV node, and the left coronary and noncoronary cusps of the aortic valve: but the supra-annular focused sites are also not reliant on purchase between tissue and direct tension-loaded penetrating/biting/holding tissue attachment mechanisms. Instead, physical structures and force distribution mechanisms such as stents, T-shaped members, and septal members can be used, which better accommodate the attachment or abutment of mechanical levers and bridge locks, and through which potential tissue tearing forces can be better distributed. Further, the anchor sites14,16do not require the operator to use complex imaging. Adjustment of implant position after or during implantation is also facilitated, free of these constraints. The anchor sites14,16also make possible full intra-atrial retrieval of the implant10by endovascularly snaring and then cutting the bridging element12at either side of the left atrial wall, from which it emerges.

Orientation of the Bridging Element

In the embodiments shown inFIGS.3A-3B, the implant10is shown to span the left atrium beginning at a posterior point of focus superior to the approximate mid-point of the mitral valve annulus, and proceeding in an anterior direction in a generally straight path directly to the region of anterior focus in the septum. The spanning region or bridging element12of the implant10may be preformed or otherwise configured to extend in this essentially straight path above the plane of the valve, without significant deviation in elevation toward or away from the plane of the annulus, other than as dictated by any difference in elevation between the posterior and anterior regions of placement. It is appreciated that such implants can include bridging member with lateral or medial deviations and/or superior or inferior deviations and can include bridging members that are rigid or semi-rigid and/or substantially fixed in length.

Posterior and Anterior Anchors

It is to be appreciated that an anchor as described herein, including a posterior or anterior anchor, describes an apparatus that may releasably hold the bridging element12in a tensioned state. As can be seen inFIGS.4A-4B, anchors20and18respectively are shown releasably secured to the bridging element12, allowing the anchor structure to move back and forth independent of the inter-atrial septum and inner wall of the great cardiac vein during a portion of the cardiac cycle when the tension force may be reduced or becomes zero.

Alternative embodiments are also described, all of which may provide this function. It is also to be appreciated that the general descriptions of posterior and anterior anchors are non-limiting to the anchor function, for example, a posterior anchor may be used anterior, and an anterior anchor may be used posterior.

When the bridging element is in an abutting relationship to a septal member (for example, anterior anchor) or a T-shaped member (for example, posterior anchor), for example, the anchor allows the bridging element to move freely within or around the septal member or T-shaped member, for example, the bridging element is not connected to the septal member or T-shaped member. In this configuration, the bridging element is held in tension by the locking bridge stop, whereby the septal member or T-shaped member serves to distribute the force applied by the bridging element across a larger surface area. Alternatively, the anchor may be mechanically connected to the septal member or T-shaped member, for example, when the bridge stop is positioned over and secured to the septal member hub. In this configuration, the bridging element is fixed relative to the septal member position and is not free to move about the septal member.

FIGS.6A-6Bshow perspectives views of an example locking bridge stop20in accordance with the present invention. Each bridge stop20preferably includes a fixed upper body302and a movable lower body304. Alternatively, the upper body302may be movable and the lower body304may be fixed. The upper body302and lower body304are positioned circumjacent a tubular shaped rivet306. The upper body302and lower body304are preferably held in position by the rivet head308and a base plate310. The rivet306and base plate310includes a predetermined inner diameter312, sized so as to allow the bridge stop300to be installed over a guidewire. A spring, such as a spring washer314, or also known in the mechanical art as a Belleville Spring, is positioned circumjacent the rivet306and between the rivet head308and the upper body302, and applies an upward force on the lower body304. The lower body304is movable between a bridge unlocked position (seeFIG.6A), and a bridge locked position (seeFIG.6B). In the bridge unlocked position, the lower body304and the upper body302are not in contacting communication, creating a groove320between the upper body302and lower body304. In the bridge locked position, the axial force of the spring washer314urges the lower body304into contacting, or near contacting communication with the upper body302, whereby the bridging element12, which has been positioned within the groove320, is locked in place by the axial force of the lower body304being applied to the upper body302. In use, the bridging element12is positioned within the groove320while the lower body304is maintained in the bridge unlocked position316. The bridge stop300is positioned against the septal member30and the bridging element12is adjusted to proper tension. The lower body304is then allowed to move toward the upper body302, thereby fixing the position of the bridge stop300on the bridging element12. While this example depicts a particular locking bridge stop design, it is appreciated that any suitable lock could be used, including any of the types described in U.S. Patent Application Publication No. 2017/0055969.

FIGS.7A-7Bshow alternative heart implants suitable for delivery with the methods and delivery systems described herein.FIG.7Ashows an implant10′ having a T-shaped posterior anchor18in the great cardiac vein and T-shaped anterior anchor70. The anterior T-shaped bridge stop75may be of a construction of any of the T-shaped bridge stop embodiments described. The T-shaped member75includes a lumen75extending through the T-shaped member75perpendicular to the length of the T-shaped member. The bridging element12may be secured by a free floating bridge stop as previously described.FIG.7Bshows an implant10″ having a T-shaped posterior anchor18in the great cardiac vein and a lattice style anterior anchor76. The lattice77is positioned on the septal wall at or near the fossa ovalis. Optionally, the lattice77may include a reinforcement strut78to distribute the bridging element12tension forces over a greater area on the septal wall. The anterior lattice style bridge stop76may be packed in a deployment catheter with the bridging element12passing through its center. The lattice77is preferably self-expanding and may be deployed by a plunger. The bridging element12may be secured by a free floating bridge stop as previously described. It is appreciated that various other such implants could be devised that utilized the same concepts as in the above described implants for delivery and deployment with the systems and methods described herein.

FIGS.8A-8Bshow alternative methods of connecting the bridging element12to a T-shaped posterior anchor.FIG.8Ashows a T-shaped member18where the bridging element12is wound around a central portion of the T-shaped member. The bridging element12may be secured by adhesive712, knot, or a securing band placed over the bridging element12, for example. Alternatively, the bridging element12may first be threaded through a lumen714extending through the T-shaped posterior anchor18perpendicular the length of the T-shaped member. The bridging element12may then be wound around the T-shaped member, and secured by adhesive712, securing band, or knot, for example.FIG.8Bshows a T-shaped member18where the bridging element12is welded or forged to a plate716. The plate716may then be embedded within the T-shaped member710, or alternatively, secured to the T-shaped member710by gluing or welding, for example. It is appreciated that various other couplings could be used to secure the bridging element12and posterior anchor18and facilitate delivery with the systems and methods described herein.

FIGS.9A-9Bdepict alternative anchors suitable for use as posterior anchors within a heart implant in accordance with the invention.FIG.9Ais a perspective view of a T-shaped anchor18′ that includes an intravascular stent80and, optionally, a reinforcing strut81. The stent80may be a balloon expandable or self-expanding stent. As previously described, the T-shaped anchor18′ is preferably connected to a predetermined length of the bridging element12. The bridging element12may be held within, on, or around the T-shaped bridge stop80through the use of any of the bridge locks as previously described, or may be connected to the T-shaped anchor18by way of tying, welding, or gluing, for example, or any combination.FIG.9Bdepicts a T-shaped anchor18″ that includes a flexible tube90having a predetermined length, for example, three to eight centimeters, and an inner diameter91sized to allow at least a guidewire to pass through. The tube90is preferably braided, but may be solid as well, and may also be coated with a polymer material. Each end of the tube90preferably includes a radiopaque marker92to aid in locating and positioning the T-shaped anchor. The tube90also preferably includes atraumatic ends to protect the vessel walls. The tube may be flexurally curved or preshaped so as to generally conform to the curved shape of the great cardiac vein or interatrial septum and be less traumatic to surrounding tissue. A reinforcing center tube93may also be included to add stiffness to the anchor and aids in preventing egress of the anchor from the great cardiac vein and left atrium wall. The bridging element12extends through a central hole94in an interior side of the reinforcing center tube93. Each of the anchors described can be straight or curvilinear in shape, or flexile so as to accommodate an anatomy. It is appreciated that various other type of anchors could be used a posterior anchor18attached to bridging element12for delivery and deployment with the systems and methods described herein.

General Methods of Delivery and Implantation

The implant systems10described herein lend themselves to implantation in a heart valve annulus in various ways. Preferably, the implants10are implanted using catheter-based technology via a peripheral venous access site, such as in the femoral or jugular vein (via the IVC or SVC) under image guidance, or trans-arterial retrograde approaches to the left atrium through the aorta from the femoral artery also under image guidance. As previously described, the implants10comprise independent components that are assembled within the body to form an implant, and delivered and assembled from an exterior to the body through interaction of multiple catheters.

Conventional Delivery Approach

FIGS.10A-12Dshow deployment of an implant10of the type shown inFIGS.3A-3Bby a percutaneous, catheter-based procedure, under image guidance using conventional methods into the femoral or jugular vein, or typically, a combination of both, such as any of those described in U.S. Patent Application Publication No. 2017/0055969.

Percutaneous vascular access is achieved by conventional methods into the femoral or jugular vein, or typically, a combination of both. As shown inFIG.10A, under image guidance, a first catheter, or GCV catheter40, is advanced into the great cardiac vein from a superior vena cava (SVC) route accessed from a neck vein (for example, jugular vein) along a GCV guidewire54. As shown inFIG.10B, the LA catheter60is advanced from the right atrium via an inferior vena cava (IVC) accessed from a femoral vein, through the septum, typically at or near the fossa ovalis, and into the left atrium. The septal wall at the fossa ovalis is punctured with a trans-septal needle and a LA guidewire74is advanced through the septum into the left atrium. Typically a large bore (12-16 French) hemostasis sheath with a “Mullins” shape is placed in the LA to act as a conduit for placement for subsequent devices to placed or removed from the LA without injuring the tissues along the pathway to or in the LA. The LA catheter60is then advanced into the left atrium athrough this sheath.

Each of catheters40,60include a magnetic head42,62, respectively, disposed along a distal portion thereof, the magnetic heads being configured to facilitate magnetic coupling when positioned at a desired orientation and position across a tissue wall between the left atrium and the great cardiac vein. As shown inFIGS.11A-11B, LA catheter60includes distal magnetic head having a N-S magnetic poles arranged axially along the catheter, while the GCV catheter40includes distal magnetic head having N-S magnetic poles arranged laterally relative a longitudinal axis of the catheter. This arrangement facilitate a transverse or perpendicular magnetic coupling between the respective catheters, as shown inFIGS.11B-11Cso as to allow passage of a penetrating element or guidewire, typically from a channel within one magnetic head into a corresponding channel of the other magnetic head. In this approach, the penetrating element is a puncturing guidewire54with a sharpened distal end. Typically, the puncturing guidewire54is advanced through a curved channel43within the magnetic head42of the GCV catheter40and enters a funnel-shaped channel67of magnetic head62of LA catheter60. While in this embodiment, the magnetic head of GCV catheter40has a single magnet, it is appreciated that various other embodiments can include a magnetic head having additional magnets oriented to facilitate a desired alignment, for example, a three-magnet head in which a center magnet has magnetic poles oriented laterally to an axis of the catheter between two magnets with poles oriented axially, such as that shown in U.S. Patent Application Publication No. 2017/0055969.

Next, as shown inFIG.12A, the penetrating guidewire is advanced through the LA catheter60until it exits the femoral artery access point at the groin. The left atrium magnetic catheter A is then replaced by a very long exchange catheter28, which is carefully pushed across the puncture site along the great cardiac vein to interface with the great cardiac vein magnetic catheter40. The exchange catheter28is pushed simultaneously with removing the great cardiac vein magnetic catheter40to avoid exposing the puncturing wire to tissue. Exposure of the puncturing wire during this process could easily slice through tissue should the wire move or become tensioned during removal or replacement of one of the catheters. This process typically requires two operators, one operator pushes the exchange catheter while the other operator simultaneously removes the great cardiac vein magnetic catheter, often while utilizing visualization techniques to ensure the two catheters remain interfaced and the puncturing wire remains covered. Once the exchange catheter28is placed from neck to groin, the puncturing wire is removed and replaced with a left atrial extension guidewire74, as shown inFIG.12B.

Next, extension guidewire74is gently retracted, causing the bridging element12to follow through the vasculature structure. If the optional exchange catheter28is used (as shown inFIGS.12A-12B), the extension guidewire74retracts through the lumen of the exchange catheter28without injuring tissues. The extension guidewire74is completely removed from the body at the femoral vein, leaving the bridging element12extending from exterior the body (preferably at the femoral sheath), through the vasculature structure, and again exiting at the superior vena cava sheath. The extension guidewire74may then be removed from the bridging element12by cutting or detaching the bridging element12at or near the interface coupling800between the bridging element12and extension guidewire74. The anterior end of the extension guidewire74is attached to one end of the bridging element (for example, suture material) while the other end of the bridging element is attached to the posterior anchor, which is retained within a posterior anchor delivery catheter115. As can be seen inFIG.12B, the extension guidewire74is gently retracted, causing the bridging element12to follow into the exchange catheter28and through the vasculature structure.

Posterior anchor120disposed within deployment catheter24is connected to the trailing end of bridging element12extending from the superior vena cava. While a T-shaped anchor is shown here, it is appreciated that various other types of posterior anchors can be used (for example, stent, half-stent, and the like). The deployment catheter24is then positioned onto or over the GCV guidewire54and abutted against exchange catheter28. The two-operator pushing and pulling process is repeated pushing the posterior anchor delivery catheter115while simultaneously removing the exchange catheter28so as to position the posterior anchor within the great cardiac vein and the bridging element extends across the left atrium.

Optionally, the bridging element12may be pulled from the femoral vein region, either individually, or in combination with the deployment catheter24, to facilitate advancement of the posterior anchor120and bridging element into position in the great cardiac vein and across the left atrium. The GCV guidewire54is then retracted letting the T-shaped anchor120separate from the GCV guidewire54and deployment catheter24. Preferably under image guidance, and once separation is confirmed, the bridging element12is gently pulled to position the T-shaped anchor120in abutment against the venous tissue within the great cardiac vein and centered over the GCV access lumen115. The deployment catheter24and exchange catheter28may then be removed. The T-shaped anchor120with attached bridging element12remain within the great cardiac vein. The length of bridging element12extends from the posterior T-shaped anchor120, through the left atrium, through the fossa ovalis, through the vasculature, and preferably remains accessible exterior the body. The bridging element12is now ready for the next step of establishing the anterior anchor region16, as previously described and as shown inFIGS.16C-16D.

Once the posterior anchor region14, bridging element12, and anterior anchor region16configured as previously described, a tension is placed on the bridging element12. The implant10and associated regions may be allowed to settle for a predetermined amount of time, for example, five or more seconds. The mitral valve and mitral valve regurgitation are observed for desired therapeutic effects. The tension on the bridging element12may be adjusted until a desired result is achieved. The anchor20is then secured the bridging element12by use of a locking bridge stop30when the desired tension or measured length or degree of mitral regurgitation reduction is achieved.

Improved Methods of Delivery and Associated Catheter Systems

In one aspect, an improved anchor delivery catheter allows for delivery and deployment of the above-described implant with fewer catheters and improved ease of use as compared to the conventional approach described above. In some embodiments, the catheter systems includes an anchor delivery catheter having a distal magnet portion that facilitates access to a heart chamber from within an adjacent vasculature by passage of a penetrating guidewire to a magnetically couple catheters within the heart chamber. In some embodiments, the anchor delivery catheter is configured for delivery of the bridging element across the heart chamber (for example, left atrium), once access is achieved, and subsequent deployment of the anchor within the vasculature (for example, great cardiac vein). In some embodiments, the bridging element is attached to a trailing end of the penetrating guidewire while the other end is attached to the posterior anchor disposed on a distal portion of the delivery catheter. This allows the bridging element to be advanced through the penetration between the heart chamber and vasculature by continued advancement of the penetrating guidewire from one vascular access point (for example, jugular vein) to exit the body at the second vascular access point (for example, femoral vein).

In some embodiments, for example, as shown inFIG.13, the above described anchor delivery is a GCV catheter50for delivery of the posterior anchor18within the GCV. Catheter50preferably includes a magnetic or ferromagnetic head52positioned along a distal portion of the catheter shaft. Optionally, a hub can be positioned on the proximal end. The catheter shaft may include a proximal section that is generally stiff to allow for torquability of the shaft, which can be of a solid or braided construction. The proximal section includes a predetermined length (for example, fifty centimeters or more), to allow positioning of the shaft within the vasculature structure. A distal section, along which the distal portion is defined, may be generally flexible to allow for steerability within the vasculature, for example, within the chamber or vasculature of the heart. The distal section can also be of a predetermined length (for example, ten centimeters or more) suitable for maneuvering within the heart. An inner diameter or lumen of the catheter shaft is preferably sized to allow passage of a GCV guidewire15, and a penetrating guidewire as well as a bridging element. The GCV catheter50preferably includes a radiopaque marker to facilitate adjusting the catheter under image guidance to align with the LA catheter60. The magnetic or ferromagnetic head52is preferably polarized to magnetically attract or couple the distal end of the LA catheter60, as described previously. Magnetic head52includes a guide channel formed therein to facilitate passage of the penetrating guidewire through the channel and into a corresponding channel in the magnetic head of the LA catheter60.

Similar to the GCV catheter50the LA catheter60preferably includes a magnetic or ferromagnetic head62positioned on a distal end thereof. The catheter shaft may include a proximal and distal sections similar to those of catheter50described above. The proximal section may be generally stiff to allow for torquability of the shaft, and may be of a solid or braided construction. The distal section includes a predetermined length, for example, ninety centimeters, to allow positioning of the shaft within the vasculature structure. The distal section may be generally flexible and anatomically shaped to allow for steerability through the fossa ovalis and into the left atrium. The distal section may also include a predetermined length, for example, ten centimeters. An inner diameter or lumen of the catheter shaft is preferably sized to allow passage of an LA guidewire74, and additionally may accept the penetrating guidewire54passed from the GCV and subsequently the bridging element12attached thereto. The LA catheter60may also include a radiopaque marker to facilitate adjusting the catheter60under image guidance to align with the GCV catheter50. The magnetic or ferromagnetic head62of the LA catheter60is polarized to magnetically attract or couple the distal end of the GCV catheter, for example, as shown inFIGS.11A-11C. It is appreciated that the magnetic forces in the head62may be reversed, as long as attracting magnetic poles in the LA catheter60and the GCV catheter50are aligned.

While a particular configuration of magnetic heads is described above, it is appreciated that various other magnetic head configurations could be used, for example, of those any of these described in U.S. Patent Application Publication No. 2017/0055969. Detailed examples of such catheter configuration are described further inFIGS.17-19.

A system of the invention that includes catheters having another magnet head configuration is shown inFIG.27. The design reduces the amount of steps the practitioner has to perform to align the magnets of the LA magnet catheter and the GCV catheter and improves visualization of the penetrating guidewire and catheter alignment during crossing of the wall of the left atrium.

With reference toFIG.27, the system includes first and second magnetic catheters.FIG.27illustrates the distal regions of the first and second magnetic catheters and shows the magnet arrangement within their respective magnetic heads. The first catheter1300, for advancement into the GVC, has a proximal end and a distal end (distal end shown inFIG.27) and includes a first lumen extending through a length of the first catheter, a first magnet1320disposed along a distal portion of the first catheter, and a first guide channel1330disposed in the distal portion of the first catheter and extending along a first longitudinal axis. In various aspects, the first magnet1320includes a first magnetic pole1340and a second magnetic pole1350. Additionally, the first guide channel1330is coextensive with the first lumen and has a first side hole1360located proximal along the distal portion of the first catheter relative to the first magnetic pole1340.

The second catheter1310, for advancement into the LA, has a proximal end and a distal end (distal end shown inFIG.27) and includes a second lumen extending through the length of the second catheter, a second magnet1370disposed at the distal end of the second catheter, and a second guide channel1380disposed at the distal end of the second catheter and extending along a second longitudinal axis. In various aspects, the second magnet1370includes a third magnetic pole1390and a fourth magnetic pole1400. Additionally, the second guide channel is coextensive with the second lumen and has a second side hole1410adjacent the second magnet1370.

The first magnet1320and the second magnet1370are configured such that they automatically align the distal portions of the first catheter1300and the second catheter1310and magnetically couple with the distal portions of the first and second catheters being substantially perpendicular to one another (approximately 90 degrees with respect to one another) upon coupling (as shown inFIG.27). As such, the first magnetic pole1340and the third magnetic pole1390are of opposite polarity and proximate each other upon magnetic coupling. For example, the first magnetic pole1340is of positive polarity and the third magnetic pole1390is of negative polarity. In this configuration, the first magnetic pole1340and the second magnetic pole1350are disposed perpendicular with respect to a longitudinal axis of the first guide channel1330and the third magnetic pole1390and the fourth magnetic pole1400are disposed parallel with respect to a longitudinal axis of the second guide channel1380with the third magnetic pole1390being distal to the fourth magnetic pole1400along the distal end of the second catheter1310. It is appreciated that the magnetic forces in first magnet1320and the second magnet1370may be reversed, as long as attracting magnetic poles in the first catheter1300and the second catheter1310are aligned.

Upon magnetic coupling of the first magnet1320and the second magnet1370, the first side hole1360and the second side hole1410are aligned in a plane parallel to a longitudinal axis of the first guide channel1330and a second longitudinal axis of the second guide channel1380such that an advancing crossing wire may traverse through the first guide channel1330and exit the first side hole1360and enter the second side hole1410and traverse the second guide channel1380. Additionally, upon magnetic coupling, the second side hole1410is oriented distal along the distal portion of the first catheter relative to the first side hole1360as shown inFIG.29. In this configuration the first side hole1360and the second side hole1410are substantially perpendicular with respect to one another.

As illustrated inFIGS.27and29, to facilitate passage of a crossing wire from the first guide channel1330and through the second guide channel1380, the second magnet1370includes a contoured recess having an arcuate or sloped surface1420oriented towards the second guide channel1380and defining a surface of the second guide channel1380. In various aspects, the arcuate or sloped surface1420extends from a distal portion of the second magnet1370to a proximal portion of the second magnet.

It will be appreciated that this configuration works by allowing the magnet catheters to attach at a 90 degree angle. The magnet shape helps the penetrating guidewire to turn into the LA catheter shaft which is attached to1380. The magnet polarity is defined such that the LA catheter magnet and the magnet1320of the GCV catheter will always attach as shown inFIG.27.

In some aspects, one or more magnets of the catheters are coated in a smooth gold coating to reduce friction during crossing. In some aspects, the second magnet1370is coated with a friction reducing material, such as gold, to reduce friction during crossing.

In addition, in some aspects, the steering tube is designed and located so that the penetrating guidewire approaches magnet1370of the LA catheter at an angle to reduce the amount of friction in the system. Further, as discussed, the magnet1370has internal geometry to help guide the penetrating guidewire into the LA catheter shaft.

To facilitate visualization of the catheters during advancement and magnetic coupling, the first catheter1300and/or the second catheter1310may include one or more radiopaque markers disposed at their respective distal ends. As shown inFIG.27, the first catheter1300includes a terminally disposed radiopaque marker1430. The second catheter1310may also include a terminally disposed radiopaque marker. In some aspects, the distal portion of the second catheter1310includes a magnet housing1440which is constructed of a material that is translucent under fluoroscopy thereby allowing the crossing wire to be viewed and/or tracked during the crossing procedure. The first and second catheters may also include additional radiopaque markers as shown inFIG.22A.

Additionally, in some aspects, the first and/or second catheter may include one or more radiopaque markers disposed along their respective lengths. For example, the first and/or second catheter may include a series of radiopaque markers disposed along their respective lengths at spaced intervals to allow the user to determine the depth of insertion of the respective catheter within the vasculature or bodily cavity.FIG.30illustrates the first catheter1300having a series of radiopaque markers1450disposed along the length of the catheter.

Further, in some aspects, the penetrating guidewire includes a nitinol wire with a Platinum/Iridium (PTIR) core to enhance the imaging of the wire and improve the practitioner's ability to see the wire at all times during a procedure.

Implantation Methods

Access to the vascular system is commonly provided through the use of introducers known in the art. A16F or less hemostasis introducer sheath (not shown), for example, may be first positioned in the superior vena cava (SVC), providing access for the GCV catheter50. Alternatively, the introducer may be positioned in the subclavian vein. A second14F or less introducer sheath (not shown and described above) may then be positioned in the right femoral vein, providing access for the LA catheter60. Access at both the SVC and the right femoral vein, for example, also allows the implantation methods to utilize a loop guidewire. For instance, in a procedure to be described later, a loop guidewire is generated by advancing a LA guidewire through the vasculature until it exits the body and extends external the body at both the superior vena cava sheath and femoral sheath. The LA guidewire may follow an intravascular path that extends at least from the superior vena cava sheath through the interatrial septum into the left atrium and from the left atrium through atrial tissue and through a great cardiac vein to the femoral sheath.

FIGS.14A-16Dillustrate a method of implantation utilizing a magnetic anchor delivery catheter in accordance with aspects of the invention.FIGS.14A-14Bdepict positioning of the GCV anchor delivery catheter50within the great cardiac vein adjacent a posterior annulus of the mitral valve. First, as shown inFIG.14A, under image guidance, the GCV guidewire15(for example, a 0.035 inch guidewire) for example, is advanced into the coronary sinus to the great cardiac vein along an SVC approach. Optionally, an injection of contrast with an angiographic catheter may be made into the left main artery from the aorta and an image taken of the left coronary system to evaluate the position of vital coronary arterial structures. An injection of contrast may also be made in the great cardiac vein in order to provide an image and a measurement. If the great cardiac vein is too small, the great cardiac vein may be dilated with a 5 to 12 millimeter balloon, for example, to midway the posterior leaflet.

As shown inFIG.14B, the GCV catheter50is advanced over the GCV guidewire15so that the distal magnetic head52and posterior anchor18are positioned at or near a desired location in the great cardiac vein, for example, near the center of the posterior leaflet or posterior mitral valve annulus. The desired position for the GCV catheter50may also be viewed as approximately 2 to 6 centimeters from the anterior intraventricular vein takeoff. Once the GCV catheter50is positioned, an injection may be made to confirm sufficient blood flow around the GCV catheter50. If blood flow is low or non-existent, the GCV catheter50may be pulled back into the coronary sinus until needed.

As shown inFIG.14C, the LA catheter60is then deployed in the left atrium. From the femoral vein, under image guidance, the LA guidewire16, a 0.035 inch guidewire for example, is advanced into the right atrium. A 7 Fr Mullins dilator with a trans-septal needle (not shown) can be deployed into the right atrium. An injection is made within the right atrium to locate the fossa ovalis on the septal wall. The septal wall at the fossa ovalis can be punctured with a trans-septal needle and the guidewire16is advanced into the left atrium. The trans-septal needle is then removed and the dilator is advanced into the left atrium. An injection is made to confirm position relative to the left ventricle. The Mullins system is removed and then replaced with a 12 Fr or other appropriately sized Mullins system. The 12 Fr Mullins system is positioned within the right atrium and extends a short distance into the left atrium and the LA catheter60is advanced into the left atrium. After advancement of the LA catheter60into the left atrium, a distal magnetic head62of the catheter is positioned in the region adjacent the great cardiac vein so as to magnetically couple with the magnetic head52of GCV magnetic catheter50, for example, as shown inFIGS.11A-11C, the magnetic heads automatically align the lumens of the LA catheter60) and GCV catheter50. Similarly, after advancement of the second magnetic catheter1310into the left atrium, a distal magnet1370of the catheter is positioned in the region adjacent the great cardiac vein so as to magnetically couple with the magnet1320of first magnetic catheter1300, for example, as shown inFIG.27. The magnets automatically align the lumens of the second LA catheter1310and first GCV catheter1300. It will be appreciated that in various aspects, any methodology of the invention may employ any appropriately sized sheath system, such as 12 Fr, 14 Fr, and the like. In one aspect, a 14 Fr sheath system is used.

As shown inFIG.14D, once magnetically coupled, puncturing guidewire54is advanced through GCV catheter50to penetrate the tissue wall between the great cardiac vein and the left atrium and enters a lumen of the magnetic head62of LA catheter60. The operator continues to advance the puncturing guidewire54through a lumen of the LA catheter60until the guidewire exits the body (for example, at the groin). Since the trailing end of the puncturing guidewire is attached to the one end of the bridging element12(for example, suture), the other end of the bridging wire being attached to posterior anchor18, once the puncturing guidewire54exits the proximal end of the LA catheter60, the puncturing wire54can be pulled proximally from the LA catheter60thereby pulling the bridging element12through the GVC catheter50, across the left atrium within the LA catheter60and through the vasculature to exit the body at the groin, all while the LA catheter60and the GVC catheter50remain magnetically coupled. This approach ensures the puncturing wire54and the bridging element12remain covered while the being drawn through the vasculature over the delicate tissues of the heart. This avoids cutting or slicing the tissue with the bridging element when pulled across the tissues and further avoids the laborious pushing and pulling procedure and use of an exchange catheter described in the conventional approach.

As shown inFIG.15A, the bridging element12extends from the posterior anchor18disposed within the distal portion of the GCV catheter50, spans the left atrium and extends through the LA catheter60and exits the body at the femoral vein. The operator can gently tug the bridging element12to remove any slack from the system and ensure it is properly positioned. In some embodiments, this action can also facilitate release of the posterior anchor18from the GCV delivery catheter50. The LA catheter60can be decoupled from the GCV catheter50and withdrawn while the bridging element remains in place, as shown inFIG.15B. Optionally, the LA catheter60can remain within the left atrium extending through the septum until the posterior anchor18is fully deployed.

As shown inFIG.15C, the GCV catheter50is adjusted, if needed, to position the posterior anchor18along the penetration for subsequent release from the catheter. The posterior anchor18can be released from the GCV delivery catheter50by proximally retracting the GCV guidewire15extending through the posterior anchor18. Optionally, the catheter configuration can include a releasable coupling feature, such as a tether903, that secures the posterior anchor18to the distal portion of GCV catheter50and extends from the proximally end so that an operator can proximally pull the tether to release the posterior anchor18. The tether can be defined as a wire or suture that frictionally engages the posterior anchor in place at one end and extends proximally from the catheter at the other end, or as a tether loop that wraps around the posterior anchor and interfaces with a feature along the distal portion of the GCV catheter and both ends extend proximally from the catheter such that pulling the tether releases. It is appreciated that various types of releasable couplings could be used including any of those described in U.S. Patent Application Publication Nos. 20070265658 and 20120016456, incorporated herein by reference in their entireties.

During the process, the GCV catheter50can be retracted slightly, particularly in embodiments where the posterior anchor18partly resides in a recessed portion of the magnetic head52. In many cases of complete or partial removal of the GCV catheter, the guidewire is left inside the GCV anchor to allow for retrieval until very end of the procedure. While in this embodiment, the posterior anchor18is an elongate member, such as a T-bar anchor, it is appreciated that various other deployment steps could be used to facilitate deployment of other types of posterior anchors. For example, when the posterior anchor18is a scaffold or stent-like structure, any suitable means of deploying such structures could be used. For example, a constraining sheath partly disposed over a self-expanding scaffold can be retracted thereby releasing the scaffold from the magnetic head portion52or a balloon expandable scaffold, or otherwise releasable scaffold can be used. Once the posterior anchor18is deployed, the GCV catheter50and GCV guidewire can be removed, as shown inFIG.15D.

As shown inFIG.16A, the posterior anchor18deployed within the great cardiac vein is attached to the bridging element12spanning the left atrium and extending through the vasculature along the IVC route to exit from the femoral vein at the groin. Since the bridging element12is not yet tensioned, there is little likelihood of cutting or damage to tissues at this point. Next, as shown inFIG.16B, an anterior anchor delivery catheter26is advanced along the bridging element12with the anterior anchor mounted with the bridging element passing through its central hub the delivery catheter26having an anterior anchor30, collapsed inside the delivery sheath, disposed in a distal portion thereof, the bridging element passing through its central hub. The collapsed anterior anchor is guided to the FO or other suitable location along the septal wall and deployed, such as shown inFIG.5B.

As shown inFIG.16C, the anterior anchor30is deployed along the septal wall with a proximal locking bridge stop20through the delivery sheath. The length of the bridging element12can then be incrementally adjusted and held in place by the bridge lock20) upon each adjustment until observation of the heart pumping indicates improved valve function. The excess bridging element12can then be cut with a cutting element of the catheter, or by use of a separate cutting catheter advanced along the bridging element12. The LA delivery catheter60can then be removed, leaving the fully deployed implant10in place within the heart, as shown inFIG.16D.

In similar embodiments, the invention provides a method of performing a surgical procedure on a subject using the system of the invention as shown inFIG.27. The method includes inserting, through a first vascular access site, the first catheter1300, and advancing the first catheter1300to a first location in or proximate a heart of the subject. The second catheter1310is inserted through a second vascular access site and advanced to a second location in or proximate the heart, the first and second locations being separated by a tissue wall of the heart. The first catheter1300and the second catheter1310are positioned such that the first magnet1320and the second magnet1370magnetically couple across the tissue wall. The tissue wall is then penetrated with a penetrating member, such as a penetrating guidewire which is advanced through the first catheter1300, across the tissue wall and through the second catheter1310while the first and second catheters are magnetically coupled. In some aspects, the method further includes determining the depth of insertion of the first and/or second catheter via radiopaque markers disposed along the respective lengths of the catheters (shown inFIG.30) before magnetic coupling of the first magnet1320and the second magnet1370. The method further includes advancing a posterior anchor and a bridging element coupled at a first end of the bridging element to the posterior anchor to the first location from the first vascular access site while the first magnet and second magnet are magnetically coupled, advancing a second end of the bridging element through the penetrated tissue wall and into the second catheter, and advancing an anterior anchor along the bridging element from the second vascular access site and deploying the anterior anchor at a third location in the heart, the bridging element spanning across a chamber of the heart as shown inFIGS.16A-16D.

FIG.36illustrates use of the catheter system of the invention to advance the posterior anchor into the GCV via the left atrium. As shown inFIG.36, as well as inFIGS.37-45, in some aspects, the posterior anchor is delivered from the left atrium into the GCV. The GCV catheter, e.g., the first catheter, while inside the GCV, is hollowed out with a hollow open section facing toward the left atrium (concave toward left atrium). The posterior anchor is guided down the LA catheter, e.g., the second catheter, and crosses the tissue and is deposited into a trough of GCV catheter. A crossing wire is needed beforehand to facilitate tracking of the posterior anchor through the crossing hole in the LA wall.

FIGS.37-45illustrate portions of a procedure in which the magnetic catheter system of the invention is being used to advance the penetrating member (e.g., the crossing wire), from the left atrium into the GCV and advancing the posterior anchor into the GCV from the left atrium.FIG.37shows the magnetics heads of the LA and GCV catheters being magnetically coupled with the GCV wall being sandwiched between the magnetic heads of the respective catheters. As shown inFIG.38, the penetrating member, e.g., crossing wire, is advanced along the lumen of the LA catheter to puncture the GCV wall and then advanced into the magnetic channel of the GCV catheter within the GCV. Next, a pusher tube is used to advance the posterior T-bar anchor across the punctured tissue into the magnetic head of the GCV catheter as shown inFIG.40. The crossing wire is then removed by withdrawal through the lumen of the LA catheter as shown inFIG.41. The LA catheter is then removed as shown inFIG.42and the GCV catheter is advanced forward in the GCV to position the posterior T-bar anchor and suture bridge as shown inFIG.43. The suture bridge is then tensioned and the GCV catheter withdrawn from the GCV thereby leaving the posterior T-bar anchor in the GCV to complete the implantation procedure as shown inFIGS.44and45.

With reference toFIGS.46-48, in some aspects, the penetrating member goes from outside-in (from LA to GCV). As shown inFIG.46, the posterior T-bar anchor is delivered to a target site in the GCV via the GCV catheter and the magnetic heads of the LA and GCV catheters are magnetically coupled.

In various aspects, the penetrating member is a pusher shaft that includes a detachable auger tip that is advanced from the left atrium side through the LA catheter. The detachable auger tip is also attached to a suture bridge. During implantation, the auger tip is advanced on the pusher shaft along the LA catheter and screwed through the left atrium wall and into the side of the posterior anchor which is sitting in a groove of the GCV catheter magnet, as shown inFIGS.47and48. The pusher shaft is then detached from the auger tip and backed out of the LA catheter leaving behind the suture bridge which is attached to the posterior anchor via the auger tip. The LA catheter is then withdrawn and the GCV catheter is withdrawn with the posterior anchor being implanted. Due to the simplicity of crossing, multiple bridges may be easily deployed in a short time. Strong magnet pairing (high counter traction force) improves the ability of the penetrating guidewire to advance and screw into the posterior anchor. In some aspects, the posterior anchor itself has a side slot which the auger tip can connect with. Also, it is envisioned that the posterior anchor may be composed of a rubber, silicone, or polymeric material that the screw tip can easily screw into. Once the screw tip is connected to the posterior anchor, the control guidewire detaches from the screw tip, leaving behind the suture bridge.

As discussed herein,FIGS.37-45further illustrate use of the magnetic catheter system of the invention in a procedure including advancing the penetrating member, e.g., the crossing wire, from the left atrium into the GCV and advancing the posterior anchor into the GCV from the left atrium.

It will be appreciated that the magnetic catheter system of the present invention (depicted inFIGS.37-45) provides an alternate means to deliver the posterior anchor to the GCV. In practice, the GCV magnet catheter, e.g., the first catheter, and the LA catheter, e.g., the second catheter, are delivered as discussed herein and a magnetic connection is made across the left atrial wall with an intended crossing/puncture site just over the P2mitral leaflet. A penetrating member, e.g., crossing wire, is delivered from the LA magnet catheter and punctures toward/into the tip of the GCV magnet catheter. In some aspects, the GCV catheter is shaped so that it receives the crossing wire tip and is deflected proximally down the catheter shaft. A posterior anchor, such as a T-bar, is advanced down the crossing wire from the LA catheter. The crossing wire and T-bar may be co-axial with the magnets of the LA catheter in one aspect (magnet cross-section must allow), or they may be side-by-side. The T-bar distal end has a tapered tip so it may penetrate through the crossing hole, allowing the T-bar to be pushed through the hole. In some aspects, there is a pushing tube behind the T-bar, pushing it across the hole. Once the T-bar is through the hole, the pushing tube may be backed out and removed. The crossing wire is removed, either by backing it out from the femoral access or advancing the puncture end all the way to the jugular access site and then pulling the wire out from there. In the procedure, the GCV catheter is advanced forward (toward AIV) or a means is provided to advance the T-bar a small distance (about ½ a T-bar length) so that when the bridging element is tensioned from the septal side, the T-bar attachment point is directly under the crossing hole. The two magnetic catheters are then completely removed from the patient.

It will be appreciated that this system and procedure simplifies the way the posterior anchor is delivered as compared to conventional delivery methods. Notably, the need to deliver a loop of suture (requiring a cassette to feed out loop) is eliminated. Additionally, there is no need for a steering tube. Further, it will be appreciated that it is possible to deliver multiple posterior anchors using this procedure without the need to remove and replace the GCV catheter each time.

Catheter Configurations

As discussed previously, one purpose of some such delivery catheter configurations is to facilitate deployment of the posterior anchor while keeping the bridging element totally within the protection of the magnetically connected catheters by combining the magnets and keeping the posterior anchor on one delivery catheter in the great cardiac vein. Examples of such delivery catheter configurations are detailed below. It is appreciated that any of the aspects or features described in certain embodiments may be utilized in various other embodiments in accordance with the concepts described herein.

FIG.17-19show anchor delivery catheter configuration in accordance with aspects of the invention. In particular, the catheter configuration allows for magnetically coupling with a corresponding catheter to establish access within a heart chamber from adjacent vasculature and delivering a heart implant in accordance with aspect of the invention. These example delivery catheters are configured for use within a GCV catheter50, within the example delivery and deployment methods depicted above. It is appreciated that the following catheter configurations can include any of the various aspect described herein (for example, length, materials, dimensions, and the like), but are not limited to the aspects described herein and could be configured as needed for a particular use or anatomy.

FIG.17shows a distal portion of a delivery catheter configuration700that includes a guidewire lumen701aextending longitudinally to facilitate advancement of the catheter along a guidewire1positioned in the vasculature of the patient (for example, within the great cardiac vein when the catheter configuration is utilized in a GVC anchor delivery catheter). The catheter can further include a puncture wire lumen701bdimensioned to allow passage of the puncture wire and subsequent passage of the bridging element12attached thereto. The catheter includes a magnetic head702configured to magnetically couple with a magnetic head722of a corresponding catheter720through a tissue wall therebetween. Magnetic head702is defined so that the magnetic poles of the magnetic head are disposed laterally relative a longitudinal axis of the catheter so as to couple in a perpendicular orientation with magnetic head722of magnetic catheter720, in a similar fashion as inFIG.11C. The magnetic head702further includes a guide channel703defined to steer puncturing guidewire54upward through an exit hole704on one side of the magnetic head702to direct the sharped distal tip55(for example, flat tip) of the puncturing guidewire54through the tissue wall and into the magnetic head722of catheter720. The magnetic head722is defined with a central channel that is funnel-shaped so as to direct the puncturing wire52into the central channel. The dashed vertical line inFIGS.17-19represents the point at which the delivery catheter extends outside the body. In any of these embodiments, the guidewire1and bridging element12and puncturing wire54can extend through a Y-arm connector to facilitate independent manual control of the guidewire1and the puncturing wire54/bridging element12. (The catheter shaft extending between the distal end portion and the Y-arm connector is not shown). In such embodiments, the length of the puncturing wire54is greater than the sum of both magnetic catheters, and the length of bridging element12is at least long enough to extend from the posterior anchor to the second access site, so that when the puncturing wire is pulled from the second access site it pulls the bridging element out the second access site. In some embodiments, the bridging element (suture) may be long enough that it remains outside the first access site until it is pulled out of the second access site. This may be desired in the unlikely event that the suture becomes disconnected from the puncturing wire before the suture is pulled out the second access site so that the operator may retrieve it by pulling on the proximal portion still out of the body. In this instance it would need to be as long as the sum of the length of the second catheter60and twice the length of the delivery catheter50since it needs to switch back as described above. It is appreciated that while the delivery catheter configuration is shown inFIG.17extending from right to left, the end portion of the catheter would extend from left to right when viewed from a front of the patient, such as shown inFIG.13.

Catheter700includes a catheter shaft705along its length, which can be formed of any suitable material, to facilitate advancement of the catheter through the vasculature. As shown, the magnetic head702is formed with a notch or contoured recess in one side, which in this embodiment is opposite the exit hole704, although could be located in any suitable location in embodiments. The notch, recess or groove709is configured to allow passage of the guidewire1and/or to receive at least a portion of posterior anchor718. In this embodiment, posterior anchor718is defined as an elongate member having a longitudinal lumen through which the guidewire1extends. It is appreciated that a posterior anchor having a longitudinal lumen through which the guidewire1extends could be utilized in any of the embodiments described herein. It is further appreciated that the posterior anchor718could be positioned partly extending within a recess of the magnetic head, extending distally of the magnetic head (as shown) or proximally, or could extend proximally and proximally and distally of the magnetic head (as shown inFIG.20) or could be disposed entirely proximal or entirely distal of the magnetic head (as shown inFIG.21).

An outer jacket706covers the magnetic head702and includes an opening over exit hole704to allow passage of the penetrating guidewire54therethrough. Typically, the outer jacket706is formed for a flexible polymer material and is defined to form a smooth interface with the catheter shaft705. The outer jackets helps maintain the magnetic head702within the catheter and may extend at least partly over the posterior anchor718to help retain the posterior anchor718during advancement of the catheter through the vasculature. Optionally, a polymeric rounded tip707can be provided on a distal end of the jacket to facilitate advancement of the catheter through the vasculature.

FIG.18shows a distal portion of a delivery catheter configuration800that includes a guidewire lumen801extending longitudinally to facilitate advancement of the catheter along a guidewire1positioned in the vasculature of the patient, within the great cardiac vein when the catheter configuration is utilized in a GVC anchor delivery catheter. The catheter can further include a puncture wire lumen801bdimensioned to allow passage of the puncture wire54and subsequent passage of the bridging element12attached thereto. The catheter includes a magnetic head802, contained within inner jacket803, that is configured to magnetically couple with a magnetic head of another catheter on an opposite side of a tissue wall, as described in other embodiments. The magnetic head includes a guide channel (not shown) to direct the puncture guidewire54through exit hole804on one side of the magnetic head and into a lumen of the other catheter when magnetically coupled. The inner jacket803includes an opening over the exit hole804to allow passage of the distal sharpened end55(for example, flat tip) of puncturing guidewire54. As shown, the posterior anchor818is defined as an expandable scaffold. Here, the expandable scaffold is self-expanding and constrained into the configuration shown by a constraining sheath806(shown as transparent for improved visibility of underlying components). Proximal retraction of the constraining sheath806allows the expandable scaffold posterior anchor818to expand and release from the inner jacket803. The bridging element12is attached to the proximal end of the puncturing guidewire54and extends back through the catheter, out through exit hole804outside of the inner jacket to a reinforcing rib819on the posterior anchor818such that once the bridging element12is passed through the exit hole and across the heart chamber and the posterior anchor818is deployed, catheter800can be withdrawn from within the deployed posterior anchor818and the implantation process can proceed with deployment of the anterior anchor, as described above. In some embodiments, deployment may further entail laterally collapsing the scaffold by pulling of bridging element12.

FIG.19shows a distal portion of a delivery catheter configuration900that includes a guidewire lumen901aextending longitudinally to facilitate advancement of the catheter along a guidewire1positioned in the vasculature of the patient, within the great cardiac vein when the catheter configuration is utilized in a GVC anchor delivery catheter. The catheter can further include a puncture wire lumen901bdimensioned to allow passage of the puncture wire54and the bridging member length extending to the preloaded posterior anchor, and in some embodiments the tether releasing wire. The catheter includes a magnetic head902(not shown) contained within an outer jacket906, the magnetic head being configured to magnetically couple with a magnetic head of another catheter, as described above. The magnetic head includes a guide channel (not shown) to direct the puncture guidewire54through an exit hole904and into a lumen of the other catheter when magnetically coupled. The outer jacket906includes an opening over the exit hole804to allow passage of the distal sharpened end55of puncturing guidewire54through exit hole904. As shown, the posterior anchor918is defined as a non-expandable scaffold. The scaffold can be secured in place by a releasable coupling, such as a suture or tether903that extends inside a lumen of the catheter to its proximal end, such that removal of the tether releases the scaffold. Release can be further facilitated by gently tugging the bridging element12advanced through the other magnetically coupled catheter. Catheter900can then be retracted and the implantation process can proceed with deployment of the anterior anchor, as described above. In some embodiments, deployment may further entail laterally collapsing the scaffold by pulling of the bridging element12.

FIG.20shows a distal portion of a delivery catheter configuration1000having a magnetic head1002and a posterior anchor1018that is disposed over a guidewire1along which the catheter is advanced through the vasculature. In this embodiment, the posterior anchor1018is mounted within a groove1009defined within the magnetic head so as to be axially “stacked” and completely overlapping the magnetic head. The magnetic head includes with a side hole1004through which the penetrating guidewire can be advanced and from which the bridging element12extends and attaches to the posterior anchor1018at attachment feature1012. The posterior anchor includes a central portion1018athat is substantially rigid and that includes the attachment feature1012and strain relief portions1018bon each end that allow flexure so that the distal portion of the catheter can have some flexibility to accommodate curvature of the vasculature through which it is advanced. In this embodiment, the system includes a reinforced guidewire lumen2(for example, braided or coiled wire lumen) to facilitate advancement of the posterior anchor and prevent kinking when advanced along a curved path. An outer jacket1006extends over the magnetic head and includes an opening over the exit hole1004and may include a distally tapered portion1007having an opening through which the posterior anchor1018can be deployed. Once the bridging element is delivered through a second catheter magnetically coupled to the delivery catheter, as described previously, the posterior anchor1018can be released by withdrawing the guidewire1and guidewire lumen2, and can be further facilitated by gently tugging the bridging element12advanced through the other magnetically coupled catheter. In some embodiments, the posterior anchor1118can be further secured by a releaseable coupling feature and released by retracting a tether, as previously described.

Previously described non-stenting “hypo-tube” posterior anchor deployment catheters, with an internal lumen dedicated to a guidewire, have relied on the bridge attachment location on the anchor to the to be aligned and mounted on the delivery catheter at or very near the exit hole of the puncturing wire in the magnet. One perceived advantage of such delivery catheter designs is that the anchor is at or immediately adjacent the puncture site at the time of the puncture and does not have to be repositioned before release from the catheter. One draw back associated with such designs is the larger profile, bulk and increased stiffness of the staked catheter elements in this distal section. Such designs where the posterior anchor is mounted within or partly within the magnetic portion of the delivery catheter, while suitable, may not always be ideal because the ability to advance the distal portion of the delivery catheter, in curves and torque the catheter in small vasculature, particularly the great cardiac vein, is compromised. Another drawback is that in order to fit the anchor and maintain relatively reduced profile, some magnet bulk is removed over past designs, which reduces its magnetic strength. This in turn makes alignment with and attachment to the mating catheter more skill dependent and may require more catheter manipulation. In order to further reduce delivery profile and increase flexibility without loss of magnetic energy, some preferred embodiments of the delivery catheter utilize an anchor that is axially offset from the magnetic head along the longitudinal axis of the catheter, for example, as shown inFIG.21.

FIG.21shows an exemplary delivery catheter configuration1100having a magnetic head1102and a posterior anchor1118that is axially offset from the magnetic head1102along a longitudinal axis of the catheter so as to be non-overlapping with the magnetic head. The posterior anchor1118is disposed over a guidewire1along which the catheter is advanced through the vasculature. In this embodiment, the magnetic head1102includes a smaller groove1109defined within the magnetic head through which the guidewire lumen2extends. The magnetic head includes a side hole1104through which the penetrating guidewire can be advanced and from which the bridging element12extends and attaches to the posterior anchor1118at attachment feature1112. The posterior anchor includes a central portion1118athat is substantially rigid and that includes the attachment features1112and strain relief portions1118bon each end that allow flexure so that the distal portion of the catheter can have some flexibility to accommodate curvature of the vasculature through which it is advanced. The strain relief portions1118bare defined as helical cut portions in the elongate tube defining the posterior anchor1118. In this embodiment, the system includes a reinforced guidewire lumen2(for example, braided or coiled wire lumen) to facilitate advancement of the posterior anchor and prevent kinking when advanced along a curved path. An outer jacket1106includes an opening over the exit hole1104and can include a distally tapered portion1107having an opening surrounding a proximal portion of posterior anchor1118and luminal extension1108. Once the bridging element is pulled through the second catheter magnetically coupled to the delivery catheter, as described previously, the posterior anchor1118can be released by withdrawing the guidewire1and guidewire lumen2, and can be further facilitated by gently tugging the bridging element12advanced through the other magnetically coupled catheter. In some embodiments, the posterior anchor1118can be further secured by a releaseable coupling feature, for example, a tether or tether loop that engages the posterior anchor to the distal portion of the catheter and that is released by retracting a tether, as previously described.

The primary feature that reduces profile and increases flexibility is the placement of the posterior anchor in front of the magnet and over a guidewire. This design leverages the natural flexural properties of the proximal of the two stress relieving atraumatic ends (for example, strain relief portions) of the posterior anchor design creating a bending point (see arrow inFIG.21) allowing the distal portion to bend or flex relative the magnetic head portion (see dotted line) to better approximate the curve of a body lumen or vasculature, such as the GCV. Compared to the larger catheter magnet tip profile section described above inFIG.20, the posterior anchor at the tip of the delivery catheter ofFIG.21better approximates the natural reducing diameter of the vasculature as the catheter is delivered, advancing it distally.

Because the bending is concentrated to single point between to quasi-rigid sections, transitional construction features can be added to aid in its translational and rotational performance during placement and inhibit kinking at the joint or binding the guidewire. On the inner diameter, a reinforced guidewire lumen2(for example, a braided or coiled wire) that spans the full length of the catheter can be used to facilitate advancement of the posterior anchor. In some embodiments, the reinforced guidewire lumen is dimensioned to substantially fill the luminal space between the guidewire and posterior anchor. The outer flexible polymeric luminal extension1108around the anchor that ends at bridging element attachment point stepwise transitions bending of the distal portion of the catheter. On the outer diameter in front of the magnet the distally tapered portion1107can be defined as a flexible conical section to limit the amount of bending over the flex point and acts as a smooth transition against the vasculature wall mitigating disparate diameters of the magnetic head and posterior anchor cross-sections.

Both designs shown inFIGS.20-21allow the delivery of hollow posterior anchors within magnetically connected delivery catheters, largely without exposure of the suture bridge to tissue.

In some embodiments, a releasable coupling, such as a tether connected to the proximal end of the delivery catheter holds the posterior anchor in place during placement and releases the posterior anchor when in place. A stacked design with the posterior anchor partly or completely overlapping with the magnetic head has the advantage of one step location and delivery, but bulk and stiffness limit its distal excursion into smaller vasculature and the design can be more difficult to construct. An offset design with the posterior anchor being offset (for example, distal or proximal of the magnetic head) allows for passage deeper into the vessel, particularly smaller vasculature, and is easier to construct, however, it may warrant an additional repositioning step for anchor delivery after the initial crossing exposing a short section of suture with magnets unconnected.

In some embodiments, the catheter may include one or more radiopaque markers to help with translational and rotational alignment of the delivery catheter and facilitate magnetic connection to the mating catheter. It is desirable to align the side hole in the magnetic head of the first catheter with an opening in the second catheter before magnetic coupling as this allows for more consistent, robust magnetic coupling while minimizing skill dependent maneuvering of the catheters to align. In some embodiments, the catheter includes two radiopaque markers that are asymmetrical in shape and/or location relative the longitudinal axis of the respective catheter so as to indicate a rotational orientation of the catheter and facilitate alignment of a side hole opening in the magnetic head of the catheter with a corresponding lumen opening in a second catheter. For example, the one or more markers can include a first marker on a side of the catheter opposite the side hole and a second marker on the same side as the side hole, the second marker being different in relative location and/or size so as to be readily distinguished from the first marker and aid in determining rotational orientation. It is appreciated that these marker schemes can be used with any of the catheter embodiments described herein.

FIG.22Adepicts one such system having a first catheter1201and second catheter1210, the first catheter1201having a magnetic head1202(for example, single, double or three piece magnet) with a side hole opening1204and the second catheter1210) having a distal opening1214to be aligned with side hole opening1204for passage of the penetrating wire therethrough to establish access between the catheter. The first catheter includes two radiopaque markers1205a,1205bthat are asymmetrical about the longitudinal axis of the first catheter to allow a user to readily determine the rotational orientation of the first catheter before the catheters are brought in close proximity and magnetically coupled. In this embodiment, the marker closest the side hole (marker1205a) extends further proximally so that it can be readily distinguished from the opposite marker1205bso that the rotational orientation of the first catheter and relative alignment of the catheters can be readily determined, as can be appreciated by the fluoroscopy image shown inFIG.22Bdepicting a system having such markers. While the markers shown are substantially rectangular and positioned as shown, it is appreciated that various other sizes, shapes and locations of the markers can be utilized in the same manner. For example, angled lines pointing to the side hole, triangles and other shapes and sizes to help indicate direction and rotational orientation may be used. Further, it is appreciated that the magnetic heads are also fluoroscopically visible such that the second catheter may not require a separate radiopaque marker.

FIG.23depicts an example method of delivering and deploying an implant with a catheter system in accordance with aspects of the invention. The method includes steps of: advancing a first catheter along a first vascular path to a vessel of the heart from a first vascular access point, the first catheter having a distal magnetic head adjacent a first anchor and advancing a second catheter along a second vascular path to a chamber of the heart from a second vascular access point, the second catheter having a distal magnetic head. Next, the first and second catheter are positioned so as to magnetically couple the distal magnetic heads across a tissue wall between the chamber and vessel of the heart. Next, penetrating the tissue wall by advancing a puncturing guidewire from the first catheter into the second catheter while magnetically coupled. Advancing the puncturing guidewire to exit from the second vascular access point and pulling the guidewire until an attached bridging element coupled to the first anchor is pulled across the heart chamber and exits at the second vascular access point while first and second catheters are magnetically coupled. The first anchor is then deployed from the first catheter and the first catheter removed. Next, one or more additional anchors can be attached to one or more other portions of the bridging element extending across the heart chamber or through associated vasculature as needed for deployment of a particular type of implant.

In some embodiments, it may be desired to displace or remove the implant after deployment removing any tension and obstruction, allowing access the mitral valve and surrounding tissue. For example, in a few patients, the implant may prove ineffective or another type of implant or procedure may need to be effected (for example, intravascular valve replacement). Therefore, it would be desirable for a method and devices that allow for subsequent removal of the implant. Removal, at least partial removal, can be effected by cutting of the bridging element. The posterior anchor can be removed by use of conventional catheter techniques, or in some embodiments, can be left in place within the great cardiac vein. The septal anchor typically does not present any concern and can be left in place. Examples of such devices for cutting the bridge element of the implant are shown inFIGS.24A-26B.

FIGS.24A-24Cshows a bridge cutting catheter210to facilitate removal of a deployed implant, such as any of those described herein, in accordance with aspects of the invention. Bridge cutting catheter210includes a curve tipped stylet211within an inside diameter of the catheter shaft to facilitate steering of the cutting tip to suture bridge12. The cutting tip includes a cutting blade212and a capture feature213. The cutting blade212includes a sharpened cutting edge along one longitudinally extending side and an angled proximal facing end surface. The capture feature213is a loop that is angled so as to capture the bridging element12and direct the bridging element to the cutting edge when the cutting catheter is proximally retracted. Since the bridging element12is tensioned within the deployed implant, this approach is advantageous in capturing and cutting the bridging element12with limited visualization. Further the shape of the loop prevents the delicate tissues of the heart from contacting the cutting edge during the procedure. In some embodiments, the cutting catheter is advanced inside a sheath. For example, the cutting catheter can be advanced inside an 8-10 F Mullins sheath that has been placed into the LA crossing the septal wall near the outer perimeter of the anterior anchor after a conventional percutaneous septodomy procedure. Some anterior anchor types will allow the delivery catheter to pass through them because of flexible or soft subcomponents or preconstructed fenestrations.

After the cutting tip is advanced from the Mullins catheter, as shown inFIG.24A, the bridge cutting catheter210is positioned beyond the tensioned bridging element12of the deployed implant and proximally retracted so as to capture the bridging element12with the capture loop. As shown inFIG.24B, once the bridging element is captured, further retraction of the bridge cutting catheter forces the bridging element upwards along the angled proximal-facing end surface of the blade and along the cutting edge, thereby cutting the bridging element, as shown inFIG.24C.

While the presence of the cut bridging element12is often not of concern, there may be instances where it is desired to substantially remove any remaining bridging element12, for example, to prevent flailing suture from entering the valve annulus and potentially interfering with placement of a valve replacement. In such instances, it may be desirable to use a tool that allow for cutting and removal of a substantial portion, or at least a majority, of the bridging element.

FIG.25shows a bridging cutting catheter with suture grip220for cutting the bridging element and removing excess suture after cutting, in accordance with aspects of the invention. Similar to the bridge cutting catheter inFIGS.24A-24C, the catheter includes a cutting head with a cutting blade222and a capture loop223that are configured and operate in a similar manner as described above. This catheter further includes a suture grip224to facilitate removal of excess suture. The catheter includes a steerable shaft221that allow the cutting tip to be steered to the bridge. In this embodiment, the shaft is a double shaft one shaft supporting the cutting tip while the other shaft supports a suture grip224that holds the bridging element during initial cutting, then operates to wind up excess suture grip, while maintaining the bridging element to allow subsequent cutting and removal of a majority of the bridging element. The suture grip224can be configured to hold the bridging element (for example, by friction fit, or between opposable members) and to wind up excess bridging element by rotation of an element extending through a shaft of the catheter.

As shown inFIG.26A, cutting catheter220is positioned adjacent the anterior anchor (not shown) and locking bridge stop30and positioned to capture tensioned bridging element12with capture loop223and hold the bridging element with the suture grip224(positioned further from the anterior anchor than the cutting blade222). After initial cutting of the bridging element12with the cutting element, as described above, the suture grip224is actuated by rotation of a rotatable member extending through the shaft. This winds up excess suture and also moves the cutting catheter adjacent the posterior anchor, as shown inFIG.26B. As the suture grip224holds the excess suture taut, a second cut can be made with cutting tip, similar to that previously described, thereby removing a majority of the bridging element. The excess suture is retained on the suture grip and removed upon removal of the cutting catheter.

System for Anatomical Vessel Insertion Depth

As discussed herein, insertion depth of a catheter of the invention may be determined in a number of different ways. For example, components of the system of the invention may be constructed of materials that are radiopaque or incorporate radiopaque features to facilitate fluoroscopic visualization. However, it will be appreciated that insertion depth may also be determined without the use of fluoroscopic visualization.

Accordingly, in embodiments, the invention provides a catheter system that allows for measuring insertion depth of a catheter within an anatomical vessel. It will be appreciated that while the present disclosure illustrates use of the system in cardiac procedures, the system may be utilized in any surgical procedure in which determination of insertion depth within an anatomical vessel is desirable. With reference toFIGS.31and32, the catheter system1500includes an elongated overtube1510, a catheter1520slidably disposed within the lumen of the overtube, and a depth measurement mechanism1530. In some aspects, the catheter1520includes a handle1540along with a coupling1550that engages an elongated shaft1560of the measurement mechanism1530. In various aspects, the depth measurement mechanism1530is slidably coupled to the handle1540via the coupling1550disposed at the proximal end of the mechanism1530and coupled to the overtube1510at a distal end of the mechanism. In some aspects, the mechanism1530is configured to measure movement of the catheter1520along the lumen of the overtube1510when the distal end of the catheter1520is advanced distal to the distal end of the overtube1510when an expandable member1570of the overtube1510is inflated within the vessel or at the entrance point from a chamber to a vessel. As such, the elongated shaft1560translates movement of the catheter1520relative to the overtube1510when the catheter is advanced distally or proximally within the lumen of the overtube.

In a related embodiment, the invention provides a method for measuring insertion depth within an anatomical vessel using the catheter system of the invention. The method includes advancing the catheter system of the invention into an anatomical vessel. The inflation member is then expanded so that the overtube remains stationary within the vessel or against the entry to a vessel in an external chamber such as the right atrium. The method further includes advancing the distal end of the catheter distal to the distal end of the overtube and measuring via the measurement mechanism a distance the distal end of the catheter is advanced distal to the distal end of the overtube, thereby measuring insertion depth of the catheter within the anatomical vessel.

During operation of the catheter system for use in a procedure to reshape the left atrium the insertion depth of the catheter is determined by a pre-screen of the patient. During the pre-screening of the subject the distance from the ostium to the P2location (or deeper if determined) of the mitral valve translated to the GCV is determined as shown inFIG.33(see distance X). The practicioner then inserts the catheter into the right atrium via the jugular vein. Once in the right atrium the practicioner will perform the fuction of expanding the expandable member1570. As the practicioner advances the catheter into the GCV the inflation member1570contacts the ostium/right atrium wall and the catheter will contiune to advance into the GCV translating out the depth of insertion of the catheter into the GCV. While this is occuring, the measurement mechanism at the handle of the catheter allows the practicioner to ensure that correct positioning of the distal end of the catheter within the GCV has been achieved for the procedure and that puncturing of the wall of the left atrium is at the correct position.

Treatment of Mitral Valve Regurgitation

As discussed herein, the systems and methods described herein are particularly useful for treatment of mitral valve regurgitation by reshaping a chamber of the heart, for example by reshaping the left atrium. As such, the invention provides a method of treating mitral valve regurgitation in a subject by reshaping a heart chamber of the subject utilizing a system as described herein. In one aspect, the method utilizes the first and second catheters shown inFIG.27. The method includes inserting, through a first vascular access site, the first catheter1300, and advancing the first catheter1300to a first location in or proximate a heart of the subject. The second catheter1310is inserted through a second vascular access site and advanced to a second location in or proximate the heart such that the first and second locations are separated by a tissue wall of the heart. The first catheter1300and the second catheter1310are then positioned such that the first magnet1320and the second magnet1370magnetically couple across the tissue wall. The tissue wall is then penetrated with a penetrating member, such as a penetrating guidewire advanced through the first catheter1300, across the tissue wall and through the second catheter1310while the first and second catheters are magnetically coupled. A posterior anchor and a bridging element coupled at a first end of the bridging element to the posterior anchor are advanced to the first location from the first vascular access site while the first magnet1320and second magnet1370are magnetically coupled. A second end of the bridging element is advanced through the penetrated tissue wall and into the second catheter1310. An anterior anchor is advanced along the bridging element from the second vascular access site and deployed at a third location in the heart with the bridging element spanning across a chamber of the heart as shown inFIGS.16A-16D. The length of the bridging element is then shortened to reshape the chamber of the heart and the second end of the bridging element coupled to the deployed anterior anchor while the chamber of the heart is reshaped so that the chamber of the heart remains reshaped. In some aspects, the method further includes determining the depth of insertion of the first and/or second catheter via the radiopaque markers disposed along the respective lengths of the catheters (as shown inFIG.30) before magnetic coupling of the first magnet and the second magnet.

Although the invention has been described with reference to the above examples, it will be understood that modifications and variations are encompassed within the spirit and scope of the invention. Accordingly, the invention is limited only by the following claims.