Adaptable Heart Valve Delivery System

Abstract

A prosthetic heart valve delivery system having one or more features that facilitate access to a target valve annulus and improve maneuverability. The system may have a flexible access sheath having an inner lumen and a proximal handle attached to an elongated flexible catheter extending distally therefrom and having an outer diameter sized to fit through the access sheath. An expandable prosthetic heart valve is crimped and positioned within the inner lumen and near the distal end of the delivery catheter. A distal tapered nosecone is attached to the delivery catheter and facilitates passage through the patient's vasculature. An inner tube extends from the proximal handle, through the delivery catheter inner lumen, through the prosthetic heart valve, and is attached to the nosecone. Finally, the system has a guidewire that extends along the delivery catheter through the proximal handle and protrudes distally from the nosecone. The system is particularly useful for transfemoral atrioventricular valve replacement.

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE This application relates generally to delivery systems for implanting prostheses within a lumen or body cavity, and more particularly to delivery systems for replacement heart valves, such as replacement mitral or tricuspid heart valves. [Background technology]

[0002] In vertebrates, the heart is a hollow muscular organ with four pumping chambers: the left and right atria and the left and right ventricles, each with its own one-way valve. The native heart valves are identified as the aortic, mitral (or bicuspid), tricuspid, and pulmonary valves, each with flexible leaflets that coapt against each other to prevent backflow.

[0003] Prostheses exist to correct the problems associated with defective heart valves. For example, mechanical and tissue-based heart valve prostheses can be used to replace defective native heart valves. More recently, considerable effort has been devoted to the development of replacement heart valves, particularly tissue-based replacement heart valves that can be delivered with less trauma to the patient than by open-heart surgery. Replacement valves are designed to be delivered through minimally invasive procedures, even percutaneous procedures. Such replacement valves often include a tissue-based valve body that is connected to an expandable frame and then delivered to the annulus of the native valve.

[0004] It has proven particularly difficult to develop prostheses, including but not limited to replacement heart valves, that can be miniaturized for delivery and then controllably expanded for controlled placement. For example, delivering a prosthesis to a desired location within the human body, such as delivering a replacement heart valve to the mitral valve, can be extremely difficult. Gaining access to perform procedures in the heart or other anatomical locations can require delivering the device percutaneously through tortuous vasculature. Adding to the difficulty, delivery systems for prosthetic heart valves have a practical maximum diameter to allow passage through the vasculature, which limits the number and types of delivery tools that can fit within the delivery catheter. Summary of the Invention [Means for solving the problem]

[0005] Disclosed herein is a prosthetic heart valve delivery system that is particularly useful for transfemoral atrioventricular valve replacement. The system incorporates one or more features that facilitate access to the target annulus and improve maneuverability. The system may have a flexible access sheath having an inner lumen and a proximal handle attached to an elongated flexible delivery catheter extending distally therefrom and having an outer diameter sized to fit through the access sheath. An expandable prosthetic heart valve is crimped and positioned within the inner lumen and near the distal end of the delivery catheter. A distal tapered nosecone is attached to the delivery catheter to facilitate passage through the patient's vasculature. An inner tube extends from the proximal handle, through the delivery catheter inner lumen, through the prosthetic heart valve, and is attached to the nosecone. Finally, the system has a guidewire that extends along the delivery catheter through the proximal handle and protrudes distally from the nosecone.

[0006] In a first aspect, the prosthetic heart valve delivery system includes a flexible access sheath having a lumen, a proximal handle, and a delivery catheter extending distally from the proximal handle. The delivery catheter has an outer diameter sized to fit through the lumen of the access sheath, the delivery catheter also being formed with a lumen extending therethrough. The system further includes an expandable prosthetic heart valve along a distal end portion of the delivery catheter adapted to be crimped and positioned within the lumen of the delivery catheter. A tapered nosecone is coupled to and protrudes distally from the distal end of the delivery catheter in an extended state, the nosecone adapted to facilitate passage of the delivery catheter through the vasculature of the patient. The nosecone is collapsible to a folded state to reduce contact with the wall of the heart, and an inner catheter extends from the proximal handle, through the lumen of the delivery catheter, through the prosthetic heart valve, and is attached to the nosecone.

[0007] The nosecone may be inflatable and deflatable. In one form, the inner catheter extends a sufficient distance into the nosecone and has an inflation port open to an inflation chamber in the nosecone to inflate and deflate the nosecone. Alternatively, the nosecone may be formed of a collapsible braided structure and the system may have a pull wire extending from the proximal handle and connected to the nosecone that when pulled causes the nosecone to collapse. Alternatively, the inner catheter is attached to a distal end of the nosecone and the system further includes a concentric tube slidable over and relative to the inner catheter and connected to a proximal end of the nosecone, where relative displacement of the inner catheter and the concentric tube causes the nosecone to collapse.

[0008] The inner catheter may extend through the entire nosecone to its distal end, and the nosecone is configured to invert on itself when the inner catheter is retracted. In one embodiment, the nosecone is formed of an elastomeric material that may be inverted on itself to a folded state. Alternatively, the nosecone is formed of a series of stacked nested layers that may be folded longitudinally in a folded state forming a tapered elongated shape in an extended state. The inner catheter may extend through the entire nosecone to its distal end, and the nosecone is configured to fold on itself when the inner catheter is retracted.

[0009] Another prosthetic heart valve delivery system includes a flexible access sheath having an inner lumen, a proximal handle, and a delivery catheter having an elongated tube attached to and extending distally therefrom. The elongated tube has an outer diameter sized to fit through the inner lumen of the access sheath and also has an inner lumen extending to a distal end. The expandable prosthetic heart valve is crimped and positioned within the inner lumen of the delivery catheter near the distal end of the delivery catheter. Finally, a tapered nosecone protrudes distally from the distal end of the delivery catheter and is adapted to facilitate passage of the delivery catheter through the patient's vasculature. The nosecone is coupled to the distal end of the delivery catheter such that in a first configuration the nosecone protrudes from the distal end of the delivery catheter and in a second configuration the nosecone does not protrude from the distal end of the delivery catheter.

[0010] In the above system, the nosecone is attached with an interference fit to the distal end of the delivery catheter, a retraction wire extends along the delivery catheter and is connected to a distal portion of the nosecone, and pulling the retraction wire displaces the nosecone laterally from the distal end of the delivery catheter to the second configuration. Alternatively, the nosecone comprises a tubular body extending from the exterior of the delivery catheter and terminating at a distal end of a retractable nose, the retractable nose comprising two or more flap extensions of the tubular body that come together beyond the distal end of the delivery catheter. The tubular body is slidable over the delivery catheter such that retraction of the tubular body pulls the retractable nose proximally about the delivery catheter to the second configuration.

[0011] A third prosthetic heart valve delivery system disclosed herein includes a flexible access sheath having an inner lumen, a proximal handle, and an elongated flexible delivery catheter having an elongated tube attached to and extending distally therefrom. The elongated tube has an outer diameter sized to fit through the inner lumen of the access sheath and also has an inner lumen extending to a distal end. The expandable prosthetic heart valve is crimped and positioned within the inner lumen of the delivery catheter near the distal end of the delivery catheter. A tapered nosecone projects distally from the distal end of the delivery catheter and is adapted to facilitate passage of the delivery catheter through the patient's vasculature. Additionally, a guidewire has a sufficient length to extend along the delivery catheter from a location proximal to the proximal handle and project distally from the nosecone. The guidewire extends along a non-centered path within the delivery catheter to the distal end of the delivery catheter where it passes through an angled channel formed in the nosecone so as to protrude centrally and distally from the nosecone. The guidewire may extend through a longitudinal passage formed in the wall of the delivery catheter before reaching the distal end of the delivery catheter, or the guidewire extends outside of the delivery catheter before reaching the distal end of the delivery catheter.

[0012] Four disclosed prosthetic heart valve delivery systems include a flexible access sheath having an inner lumen, a proximal handle, and an elongated flexible delivery catheter having an elongated tube attached to the proximal handle and extending distally therefrom. The elongated tube has an outer diameter sized to fit through the inner lumen of the access sheath and also has an inner lumen extending to a distal end. The expandable prosthetic heart valve is crimped and positioned within the inner lumen of the delivery catheter near the distal end of the delivery catheter. A tapered nosecone is attached to the distal end of the delivery catheter and adapted to facilitate passage of the delivery catheter through the patient's vasculature. Additionally, an inner tube extends from the proximal handle, through the inner lumen of the delivery catheter, through the prosthetic heart valve, and is attached to the nosecone, the inner tube functions as an inflation tube and is connected to an inflation fluid source via the proximal handle.

[0013] In a fourth system embodiment, the nosecone is optionally inflatable and deflatable, with the inner tube having an inflation port open to an inflation chamber in the nosecone for inflating and deflating the nosecone. Alternatively, the nosecone has a solid body surrounded by an outer balloon, with the inner tube having an inflation port open to an interior of the outer balloon for inflating and deflating the outer balloon. Still further, the prosthetic heart valve may be balloon expandable, with the system further including a balloon surrounding the inner tube, the balloon within the crimped prosthetic heart valve, with the inner tube having one or more side ports open to an interior space of the balloon for inflating the balloon to expand the prosthetic heart valve.

[0014] Also, in a fourth system embodiment, the seal may be positioned at the distal end of the inflation tube that includes an elastomeric member that seals in the absence of an instrument. The seal may include a single annular member with a conical proximal lead-in wall and a central opening for passage of an instrument. Alternatively, the seal may include a duckbill type valve with two elastomeric flaps that are angled toward each other and project proximally. The seal may have a lead-in seal that includes an elastomeric conical member that is angled distally and positioned just proximal to the duckbill type valve to facilitate passage of a guidewire through the duckbill type valve.

[0015] A fourth system embodiment may further include a septal stabilization balloon positioned within the delivery catheter proximal to the nosecone, the septal stabilization balloon having a spool shape with a central circular groove sized to receive the septal wall and two annular lobes flanking the central circular groove sized to contact opposite sides of the septal wall, the inner tube having one or more side ports opening to an interior space of the septal stabilization balloon for inflating the septal stabilization balloon.

[0016] A still further prosthetic heart valve delivery system includes a flexible access sheath having an inner lumen, a proximal handle, and an elongated flexible delivery catheter having an elongated tube attached to and extending distally therefrom. The elongated tube has an outer diameter sized to fit through the inner lumen of the access sheath and also has an inner lumen extending to a distal end. The expandable prosthetic heart valve is crimped and positioned within the inner lumen of the delivery catheter near the distal end of the delivery catheter. A tapered nosecone projects distally from the distal end of the delivery catheter and is adapted to facilitate passage of the delivery catheter through the patient's vasculature. Also, a guidewire having a sufficient length to extend along the delivery catheter from a location proximal to the proximal handle and project distally from the nosecone includes a central core surrounded by an insulated outer coil. The central core and outer coil are electrically connected at the distal end of the guidewire to form a circuit and connected to opposite poles of an electrical source to selectively initiate electrical current through the circuit. The separate section of the guidewire central core may be configured to transform from a flexible configuration to a stiffer configuration upon initiation of electrical current and resulting heating of the guidewire. The guidewire may terminate in a distal atraumatic pigtail, and the separate section may be located just proximal to the pigtail.

[0017] A sixth prosthetic heart valve delivery system disclosed herein includes a flexible access sheath having an inner lumen, the access sheath having a wall structure that allows the access sheath to be transformed between a rigid configuration and a flexible configuration. An elongated flexible delivery catheter has an elongated tube attached to a proximal handle and extending distally therefrom, the elongated tube having an outer diameter sized to fit through the inner lumen of the access sheath, the elongated tube also having an inner lumen extending to a distal end. The expandable prosthetic heart valve is crimped and positioned within the inner lumen of the delivery catheter near the distal end of the delivery catheter. Finally, a tapered nosecone is attached to the distal end of the delivery catheter and adapted to facilitate passage of the delivery catheter through the patient's vasculature. The access sheath may include an inner tubular member surrounded by an expandable filament coiled about the tubular member, the filament connected to a fluid source to transform the filament from a contracted state to an expanded state, thus stiffening the access sheath to a rigid configuration. The inner tubular member may have longitudinal pleats that allow for radial compression of the access sheath when the filament is in its contracted state.

[0018] A seventh prosthetic heart valve delivery system features a flexible access sheath having an inner lumen, the access sheath having a wall structure that allows the access sheath to be transformed between an extended configuration and an axially collapsed configuration. An elongated flexible delivery catheter having an elongated tube is attached to and extends distally from a proximal handle, the elongated tube having an outer diameter sized to fit through the inner lumen of the access sheath, the elongated tube also having an inner lumen extending to a distal end. An expandable prosthetic heart valve is crimped and positioned within the inner lumen of the delivery catheter near the distal end of the delivery catheter, and a tapered nosecone is attached to the distal end of the delivery catheter and adapted to facilitate passage of the delivery catheter through the patient's vasculature.

[0019] In a seventh system, the access sheath may include an axially compressible structure within the outer jacket comprising a series of axially spaced rings joined with a plurality of axially compressible struts between adjacent rings. For example, the axially compressible struts may have a serpentine or zigzag configuration. The axially compressible struts between any two pairs of adjacent rings may be rotationally offset between pairs of rings sequentially along the access sheath.

[0020] Still further eight prosthetic heart valve delivery systems include an elongated flexible delivery catheter having an elongated tube attached to a proximal handle and extending distally therefrom, the elongated tube having an outer diameter and an inner lumen extending to a distal end. The expandable prosthetic heart valve is crimped and positioned within the inner lumen of the delivery catheter near the distal end of the delivery catheter. Additionally, a breakaway tip fitted onto the delivery catheter comprising a flexible tubular bag having seals at distal and proximal ends that contact the exterior of the delivery catheter, and a tapered distal end having petals. The breakaway tip forms a hemostatic barrier around the delivery catheter, the petals adapted to bend outward upon distal advancement of the delivery catheter relative to the breakaway tip to allow the delivery catheter to be advanced from within the breakaway tip. The breakaway tip may have an outward flange on the proximal end configured to contact the exterior of the patient access site and stop further distal movement of the breakaway tip. The seals at the distal and proximal ends are preferably O-rings.

[0021] A ninth prosthetic heart valve delivery system disclosed herein comprises an elongated flexible delivery catheter having an elongated tube attached to a proximal handle and extending distally therefrom, the elongated tube having an outer diameter and an inner lumen extending to a distal end. The expandable prosthetic heart valve is crimped and positioned within the inner lumen of the delivery catheter near the distal end of the delivery catheter. A flexible access sheath has an inner lumen, and the delivery catheter is sized to fit through the inner lumen of the access sheath. Finally, a breakaway tip fitted over the access sheath and delivery catheter comprises a flexible tubular bag having a proximal seal at a proximal end that contacts the exterior of the access sheath and a distal seal at a distal end that contacts the exterior of the delivery catheter, and a tapered distal end with petals. The breakaway tip forms a hemostatic barrier around the access sheath and delivery catheter, and the petals are adapted to bend outward upon distal advancement of the delivery catheter relative to the breakaway tip to allow the delivery catheter to be advanced from within the breakaway tip.

[0022] In any of the aforementioned systems, the delivery catheter may include a motor in the proximal handle and a puller wire extending from the proximal handle to a distal tip of the elongate tube, the puller wire connected to steer the catheter by deflecting the distal tip in multiple directions. The motorized system may further include a controller configured to control operation of the motor including input devices, output devices, a memory, and a processor, the controller may be connected to a power source.

[0023] In any of the aforementioned systems, a catheter positioning sensor may be inserted along the delivery catheter into the tricuspid annulus, the sensor having a node on a distal end configured to emit an RF field. The delivery catheter has the sensor positioned to be recognized by the emitter so that the relative position of the delivery catheter sensor can be communicated to a user display. The node may be a single node point emitter, an adjustable ring radiator, or an adjustable ring radiator.

[0024] In any of the aforementioned systems, the prosthetic heart valve may include at least one access port extending axially therethrough for passage of a wire lead without passing through the leaflets of the valve.

[0025] A further understanding of the nature and advantages of the present invention may be realized by reference to the remaining portions of the specification and drawings. [Brief description of the drawings]

[0026] The features and advantages of the present invention will be recognized as they become better understood with reference to the specification, claims, and accompanying drawings.

[0027] [Figure 1] FIG. 1 is a schematic diagram of a transvascular method of introducing a flexible catheter into the heart to perform a procedure such as valve replacement at the mitral annulus. [Figure 1A] FIG. 1A is an enlarged view of the heart alone showing a similar catheter advanced through the vasculature to the tricuspid annulus. [Diagram 2] 2A-2D are cross-sections of a heart illustrating the sequential steps in a typical mitral valve replacement procedure utilizing a valve delivery system. [Diagram 3] FIG. 3 is a longitudinal cross-sectional view through a distal section of a conventional valve delivery system. [Figure 4]4A and 4B are cross-sectional views of an inflatable nose cone that may be used with the valve delivery system of FIG. 3, in inflated and deflated configurations, respectively. [Diagram 5] FIG. 5A illustrates an alternative foldable nosecone formed from a braided material, while FIGS. 5B and 5C show different ways to fold the nosecone. [Figure 6] 6A and 6B illustrate a foldable / invertible nose cone in extended and inverted configurations, respectively. [Figure 7] FIG. 7A shows a removable nosecone secured to the distal end of a delivery catheter, and FIG. 7B shows one way to remove the nosecone. [Figure 8] 8A and 8B illustrate a retractable nosecone. [Figure 9] FIG. 9 is a radial cross-sectional view taken along line 9-9 of FIG. 3 through a crimped valve held within a valve delivery system, illustrating the conventional placement of a guidewire therethrough. [Figure 10] 10A and 10B are radial cross-sectional views similar to that of FIG. 9 showing an alternative route for the guidewire through the valve delivery system. [Figure 11] FIG. 11 is a longitudinal cross-sectional view through an alternative nosecone adapted to provide an angled path for a guidewire routed external to a delivery catheter, for example as shown in FIG. 10B. [Figure 12] 12A and 12B are schematic diagrams of the distal end of a delivery catheter showing a further alternative nosecone in an extended and collapsed state. [Figure 13] 13A and 13B show the distal end of the delivery catheter and yet a further foldable nose cone in both an extended and folded state. [Figure 14] FIG. 14 is a longitudinal cross-section through the inflatable nose cone illustrating the distal seal within the guidewire tube which also doubles as the inflation lumen. [Figure 15]15A and 15B are close-up views of the distal end of the inflatable nosecone illustrating an alternative version of the distal seal. [Figure 16] FIG. 16A is a close-up view of the distal end of an alternative nosecone showing an alternative distal seal, FIG. 16B shows the passage of a guidewire through the seal, and FIG. 16C shows the addition of a lead-in seal to facilitate passage of the guidewire. [Figure 17] FIG. 17 is a schematic diagram of a system for providing fluid to a guidewire tube that also doubles as an inflation tube. [Figure 18] 18A and 18B are longitudinal cross-sectional views of yet a further nosecone having an outer balloon that may be inflated and deflated via a dual guidewire / inflation tube. [Figure 19] FIG. 19 is a longitudinal cross-sectional view through a distal section of a valve delivery system with a portion of the crimped valve removed to illustrate the dual guidewire / inflation tube that may be used to inflate the valve expansion balloon. [Figure 20] FIG. 20 illustrates the expansion of a balloon within an expandable prosthetic heart valve, such as one similar to that shown implanted in the sequence of FIGS. 2A-2C. [Figure 21] FIG. 21 is a longitudinal cross-sectional view through a distal section of a valve delivery system incorporating a septal stabilization balloon. [Figure 22] 22A-22C are cross-sections of the heart showing successive steps in deploying the septal stabilization balloon of FIG. [Diagram 23] FIG. 23 illustrates an exemplary convertible guidewire having portions that may be stiffened if desired. [Figure 24] 24A-24C illustrate a series of uses of the convertible guidewire of FIG. [Diagram 25] FIG. 25 is a schematic diagram of a transvascular approach to introduce a flexible catheter into the heart to perform a procedure, illustrating the tortuous vasculature pathways that present challenges to the procedure. [Figure 26]FIG. 26 is a diagram of the overall valve delivery system illustrating the relative movement between the control handle and the inner catheter with respect to the access sheath. [Figure 27] FIG. 27 illustrates a convertible access sheath, such as that used in the system of FIG. 26, having an expandable stiffening helix thereon. [Figure 28] 28A-28C are radial cross-sectional views illustrating alternative configurations of the convertible access sheath of FIG. [Figure 29] FIG. 29 is a schematic diagram of the proximal end of a convertible access sheath illustrating the capability of axial compression. [Diagram 30] FIG. 30 is an elevational view of an alternative compressible access sheath in an extended configuration, with FIG. 30A being an enlarged view of a portion thereof. [Diagram 31] FIG. 31 is an elevational view of the compressible access sheath of FIG. 30 showing axial compression thereof. [Diagram 32] 32A and 32B are enlarged views of several links in an alternative compressible access sheath in an extended configuration and an axially compressed configuration, respectively. [Diagram 33] FIG. 33 is a diagram of the overall valve delivery system illustrating the forward movement of the control handle and inner catheter along with the access sheath. [Diagram 34] FIG. 34 illustrates the distal end of an access sheath with a breakaway delivery system tip incorporated thereon, and FIG. 34A shows an alternative in which the breakaway delivery system tip forms the access sheath. [Diagram 35] FIG. 35 shows a breakaway delivery system tip; [Diagram 36] 36A-36B show distal displacement of the access sheath through the tip. [Figure 37] FIG. 37 illustrates a steerable delivery catheter capable of multiple planes of deflection and with motorized and sensor-affected control, FIG. 37A is a close-up view of its distal tip. [Figure 38]FIG. 38 illustrates a cross section of a control handle of a steerable delivery catheter including a motor; [Figure 39] FIG. 39 is a cross-section of the elongate shaft of the catheter, showing a puller wire extending axially therethrough. [Diagram 40] FIG. 40 illustrates the use of a catheter positioning sensor deployed adjacent to the target tricuspid annulus. [Diagram 41] FIG. 41 illustrates the use of a catheter positioning sensor deployed adjacent to the target tricuspid annulus. [Diagram 42] FIG. 42 illustrates a modified prosthetic heart valve implanted in the tricuspid annulus and having through holes for the passage of sensor wires. [Diagram 43] 43A and 43B are perspective and plan views of a modified prosthetic heart valve. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] The right and left ventricles are separated from the right and left atria by the tricuspid and mitral valves, i.e., atrioventricular valves, respectively. A septal wall extends between the right and left atria. The present specification and drawings provide aspects and features of the present disclosure in the context of several embodiments of replacement heart valves, delivery systems, and methods configured for use within a patient's vasculature, such as for replacing a patient's native heart valve. Although valve replacement at the mitral or tricuspid annulus is the primary focus of this application, certain characteristics of the delivery system described herein may equally be used for other valve implant locations, and thus the claims should not be constrained to mitral or tricuspid valve replacement unless expressly limited thereto.

[0029] In particular, a prosthetic valve delivery system is described herein for transfemoral percutaneous delivery of a replacement mitral valve to treat patients with moderate to severe mitral regurgitation. In some cases, for safety and / or other reasons, the disclosed prosthetic device may be delivered from the atrial side of the atrioventricular annulus. For example, a transatrial approach can be performed through the atrial wall, which can be accessed, for example, by an incision through the chest. Atrial delivery can also be performed endovascularly, such as from a pulmonary vein. The prosthetic valve can be delivered to the right atrium via the inferior or superior vena cava. In some cases, left atrial delivery can be performed via a transseptal approach (FIGS. 2A-2D). In the transseptal approach, an incision can be made in the atrial portion of the septal wall SW to allow access from the right atrium to the left atrium. The prosthetic valve can also be delivered via a transventricular, transatrial, or transfemoral approach with small or minimal modifications to the delivery process.

[0030] FIG. 1 illustrates an embodiment of a delivery device, assembly, or system 20. The delivery system 20 can be used to deploy a prosthesis, such as a replacement heart valve, in a body. The replacement heart valve can be delivered to the mitral annulus or other heart valve location of the patient's heart in a variety of ways, such as by open chest surgery, minimally invasive surgery, and percutaneous or transcatheter delivery through the patient's vasculature. Examples of transfemoral approaches are described in U.S. Patent Nos. 10,004,599 and 10,813,757, which are incorporated by reference herein in their entireties. Although the delivery system 20 is described in the context of a percutaneous delivery approach, and more specifically a transfemoral delivery approach, it should be understood that the features of the delivery system 20 can be applied to other delivery systems, including delivery systems for transapical delivery approaches.

[0031] The valve delivery system 20 has a proximal handle 22 from which an elongated access sheath 24 extends distally. The access sheath 24 is shown extending into the lower part of the venous system, e.g., into the ipsilateral femoral vein, and a delivery catheter 26 is advanced from within the access sheath 24 up through the patient's venous system into the right atrium to access the tricuspid valve, or into the left atrium with further transseptal puncture using known techniques to access the mitral valve. FIG. 1 illustrates the latter procedure, with the distal tip 28 (see FIG. 2A) of the delivery catheter 26 crossing the septal wall SW, while FIG. 1A illustrates the distal tip in the right atrium. Both procedures are enhanced by the various delivery system attributes described herein, either individually or in conjunction with one another. All combinations of the structural features described herein are contemplated, assuming they are not mutually exclusive or redundant in deployment.

[0032] It should be noted that the access sheath 24 may be integrally associated with the proximal handle 22 or may be a separate device. In this context, an integral sheath 24 is fixedly attached to the proximal handle 22 and the delivery catheter 26 extends through and is movable relative to both the handle 22 and the sheath. In a separate sheath 24, the sheath has a proximal hub with an elastomeric valve and the delivery catheter 26 is fixedly attached to the proximal handle 22 and passed through the valve to prevent blood leakage. Both types of access sheaths 24 are contemplated herein and the claims should not be considered limited to one or the other unless specifically recited.

[0033] It should be noted that the proximal handle 22 and associated support systems, such as guidewires and inflation connections, are generally known in the art. Indeed, the proximal handle 22 may be closely structurally similar to those used in the Transfemoral EVOQUE Tricuspid Valve Replacement System and the EVOQUE Transcatheter Mitral Valve Replacement System, both developed by Edwards Lifesciences of Irvine, Calif. Aspects of the proximal handle 22 are described in the aforementioned U.S. Patents 10,004,599 and 10,813,757.

[0034] Exemplary Transvascular Heart Valve Delivery To better understand certain aspects of the improvements disclosed herein, a typical mitral valve replacement procedure utilizing valve delivery system 20 will be described with reference to Figures 2A-2D. Because this procedure is known in the art, the figures are labeled "Prior Art," however, the same procedure can be performed with one or more of the advantageous features described herein, as noted in the context below.

[0035] To deliver the prosthetic valve to the native mitral annulus, the prosthetic valve can be radially crimped into a collapsed configuration within the delivery catheter 26 of the delivery system 20. In some embodiments, the prosthetic valve can fit inside a 30 French (F) catheter (in the collapsed state). In some embodiments, the prosthetic valve can be configured to fit within an even smaller catheter, such as a 29F, 28F, 27F, or 26F catheter.

[0036] 1 and 2A, the access sheath 24 of the delivery system 20 can be placed in the ipsilateral femoral vein, and the delivery catheter 26 can be advanced through the sheath toward the right atrium. A transseptal puncture using known techniques can then be performed to gain access to the left atrium. The delivery catheter 26 can then be advanced into the left atrium and then into the left ventricle. A guidewire 30 may be necessary to position the delivery catheter 26 in the appropriate location, and one or more guidewires may be used. Additionally, a generally conical or otherwise tapered nose cone 32 is conventionally secured to the distal end 28 of the delivery catheter 26 to aid in passing through the vasculature and other obstacles, such as the septal wall SW, and through the valve leaflets VL into the associated ventricular cavity VC.

[0037] It may be advantageous for the user to be able to steer the delivery system 20 through complex areas of the heart to position the replacement mitral valve in a position consistent with the native mitral valve. For example, the user can steer the distal end 28 of the delivery catheter 26 to the appropriate area by steering or bending. The user can then continue to pass the bent delivery system 20 through a transseptal puncture into the left atrium, and then further manipulate the delivery system 20 to create an even larger bend in the delivery catheter 26. Additionally, the user can apply torque to the entire delivery system 20 to further manipulate and control the position of the distal end 28. The delivery catheter 26 is further advanced such that the delivery catheter 26 (carrying the prosthetic valve) extends between the native leaflets of the mitral valve and into the left ventricle VC.

[0038] 2B-2C show an exemplary prosthetic valve delivery including a process of expanding the prosthetic valve 40 using a delivery catheter 26 with reference to an embodiment of a prosthetic valve having a self-expanding frame, although the delivery assembly and method are applicable to other frame embodiments, such as balloon-expandable frames. In the delivery configuration (FIG. 2A), the delivery catheter 26 was previously advanced over the folded prosthetic valve to convert the valve to a radially folded configuration. Although not shown, the prosthetic heart valve 40 is typically mounted on the distal end of a delivery catheter that has the ability to displace the valve relative to the delivery catheter 26 or vice versa. As mentioned, such a delivery catheter may incorporate an expansion balloon if the valve is balloon-expandable.

[0039] 2B shows the initial phase of expanding the prosthetic valve by retracting the delivery catheter 26 from the nose cone 32, allowing for eventual expulsion of the valve. As mentioned, the nose cone 32 is useful for facilitating access of the delivery catheter 26 throughout the entire delivery system (through hemostatic valves and the like), as well as through the vasculature, potentially through the septal wall SW, and through any annulus in which the prosthetic valve will be implanted. The nose cone 32 is somewhat sharp and elongated, which reduces the amount of space available within the ventricle for manipulation of the distal end of the catheter and placement of the valve. In fact, some patients have such small space within the diseased ventricle, particularly the right ventricle, that they are screened out from undergoing this particular procedure. Thus, reduction in the size of the nose cone 32 after it is useful is one of the aims of the present application.

[0040] 2B illustrates partial retraction of delivery catheter 26 to eject a circumferential array of multiple ventricular anchors 42 from the distal end of the prosthetic valve. Heart valve 40 is displaced relative to delivery catheter 26, for example, by advancing a pusher device distally relative to the prosthetic valve and / or retracting the delivery catheter relative to the valve. End portions 44 of anchors 42 are biased to extend proximally (toward the body of the valve) when deployed. It should be understood that a restraining or constraining force exerted by delivery catheter 26 on anchors 42 can force end portions 44 to extend downwardly (in a generally distal direction away from the body) during delivery.

[0041] Once the prosthetic valve 40 is delivered to the native annulus region, the delivery catheter 26 can be further retracted relative to the prosthetic valve 40, thereby allowing the prosthetic valve 40 to expand radially outward. Release of the prosthetic valve 40 can be performed in stages. Specifically, the ventricular anchors 42 can be released from the delivery catheter 26 (FIG. 2B) prior to release of the body portion of the valve 40, as shown in FIG. 2C. When the ventricular anchors 42 are released, they spread apart away from the body, with the distal end portions 44 pointing radially outward and upward. Release of the body then causes the anchors 42 to rotate toward the body such that the distal end portions 44 pivot toward the vertical (longitudinal) axis and wrap around the back of the ventricular native valve leaflet VL.

[0042] The surgeon then optionally repositions the partially retracted valve 40 as desired and further retracts the delivery catheter 26 to engage the ventricular anchor 42 with the native annulus (FIG. 2C). The rounded head portion 46 of the ventricular anchor 42 can contact the ventricular side of the native annulus and / or adjacent tissue (e.g., the trigonal area). In particular, the anchor 42 can be configured to point more clearly upward when fully deployed compared to when it is partially deployed from the delivery catheter 26. At this point, the user can assess the engagement of the ventricular anchor 42 with the native annulus (e.g., via imaging means) before further retracting the delivery catheter 26 to deploy the atrial portion 48, as in FIG. 2D.

[0043] In some implementations, one or more ventricular anchors 42 engage the chordae tendineae, one or more ventricular anchors engage the trigonal area, and / or one or more ventricular anchors engage the native leaflets at the A2 and / or P2 locations (i.e., between the commissures of the native leaflets). The ventricular anchors, which engage the native leaflets and the trigonal area, can capture or "sandwich" the native tissue between the outer surface of the body of the prosthetic valve and the ventricular anchor (or a portion thereof) such that the tissue is compressed and engaged by the body of the prosthetic valve on one side and by the ventricular anchor on the other side. In some embodiments, due to the capture of the native tissue (e.g., the native leaflets) between the ventricular anchor and the body, the native tissue forms a seal around the body (through 360 degrees) in the left ventricle that prevents blood from moving along the exterior of the body. Because of their relatively thin profile, and because the ventricular anchors are not interconnected to one another, the distal ends of the ventricular anchors adjacent the chordae tendineae can pass between the individual chordae extending from the native leaflets, allowing the anchors to bend / pivot upward and assume their fully deployed position.

[0044] Finally, as shown in FIG. 2D, the delivery catheter 26 is further retracted to release the atrial portion 48 of the prosthetic valve 40. The atrial portion 48 forms a seal against the native annulus in the left atrium. The seal created in the left atrium by the atrial portion 48 and the seal created in the left ventricle by the ventricular anchor 42 together prevent, reduce, or minimize the flow of blood between the native annulus and the exterior of the body during diastole and systole. In some embodiments, the body and the atrial portion 48 are released simultaneously, while in other embodiments, the body is released before the atrial portion 48. Upon full deployment of the ventricular anchor 42 and the body, the distal end portion 44 can be positioned against the native annulus and / or adjacent tissue (e.g., trigone area). Thus, all stages of deployment of the prosthetic valve 40 can be controlled by the delivery catheter 26 without the need for additional actuation or manipulation.

[0045] Challenges of Transvascular Heart Valve Delivery The foregoing discussion of transvascular methods of delivering a heart valve to the mitral annulus is provided for the context of various challenges discovered during clinical investigation and commercial implementation of various available systems. There is generally an inherent conflict between navigating the sometimes complex and tortuous geometries of the vascular system and further into the cardiac structures, and providing a relatively large expandable prosthetic heart valve and associated delivery instrument. One problem is the extremely limited containment area within the delivery catheter system. Another problem is due to the relatively small space available within the heart for manipulation of valve expansion and associated features. These generalized issues become real-world problems that limit the effectiveness and ease of use of valve delivery systems.

[0046] Nosecone replacement One problem that has been identified is that the leading nosecone, shown at 32 in Figure 2A, is typically pointed and elongated, which creates the potential for damaging internal cardiac structures and further reducing the amount of space available for manipulation of the distal end of the catheter and placement of the valve. Thus, as described, various alternative nosecones are contemplated.

[0047] To better understand the structure of a conventional nosecone 32, FIG. 3 diagrammatically illustrates a longitudinal cross-section through a conventional delivery catheter 26. The nosecone 32 has an elongated, tapered front end that widens to a proximal base portion 50. The base portion 50 is preferably configured with an external step 52 that mates with and projects from the distal end 28 of the delivery catheter 26. In a conventional embodiment, the nosecone 32 engages the distal end 28 of the delivery catheter 26 with an interference or friction fit and is further secured on the distal end via attachment to an elongated guidewire tube 54. Although not shown, the guidewire tube 54 typically extends proximally throughout the delivery system 20 to the proximal handle 22. The guidewire tube 54 is hollow for passage of a guidewire, not shown here for clarity, and is fixedly secured within a through hole 56 formed in the nosecone 32 for continued passage of the guidewire therethrough. The collapsed prosthetic valve 40 is shown within the delivery catheter 26 just proximal to the nosecone 32. For better understanding, the following discussion of various alternative nosecones uses some of the same element numbers for the various features of the valve delivery system as necessary for explanation.

[0048] An embodiment of the alternative nosecone 60, shown in Figures 4A and 4B, is collapsible into a collapsed state that does not protrude distally from the distal end of the delivery catheter 26. For procedures on the tricuspid annulus, as shown in Figure 1A, a tapered nosecone or tip is not an important feature since the catheter 26 does not traverse the atrial septal puncture. In the example illustrated in Figure 4A, the nosecone 60 is an inflatable element that assumes the same or similar shape as the conventional nosecone 32 when inflated. Thus, the inflated nosecone 60 engages the end of the delivery catheter 26 and protrudes from its distal end 28 as previously described. In one embodiment, the guidewire tube 54 may incorporate a small inflation port 62 for inflating and deflating the nosecone 60. This arrangement may require a plug or seal in the lumen distal to the port 62, some embodiments of which are described below.

[0049] The inflated nose cone 60 performs essentially the same function as the conventional nose cone 32 during delivery of the prosthetic heart valve 40 to the annulus. At certain points, the benefits of the nose cone 60 are realized and its presence impedes further manipulation of the delivery catheter 26. For example, once the delivery catheter 26 is advanced into proximity with or within the target annulus, the nose cone 60 is not needed and becomes an obstacle due to its length and sharp edges.

[0050] At that point, the alternative nosecone 60 may be deflated, for example, by drawing inflation fluid through port 62 and into the guidewire tube, as shown in FIG. 4B. Once deflated and thus radially collapsed, the nosecone 60 may be retracted within the delivery catheter 26 by pulling the guidewire tube 54, as shown in FIG. 4B. Depending on size constraints, the deflated nosecone 60 may be retracted proximally through the compressed heart valve within the catheter 26, or the nosecone 60 may be temporarily advanced beyond the distal tip of the catheter 26 to allow for the passage of the expandable heart valve or other instruments used in its implantation. A typical central hole within a compressed heart valve may be 0.040 inches in diameter, which is small but potentially large enough for retraction of the proximal nosecone 60 through the valve. Alternatively, the deflated nosecone 60 may be displaced distally during the valve implant procedure, its reduced size and flaccid state rendering it essentially out of the way. It should be understood that either of these two steps may be performed for any of the foldable and removable nose cones described herein.

[0051] 5A-5C illustrate a further alternative nosecone 70, which is also collapsible into a folded state that does not protrude distally from the distal end of the delivery catheter 26. Specifically, the nosecone 70 comprises a form of a plurality of interwoven struts 72 such that in the expanded configuration, as in FIG. 5A, the nosecone 70 has the same or a similar shape as the conventional nosecone 32. Again, the expanded nosecone 70 is secured onto and protrudes from the distal end of the delivery catheter 26 and may be separately manipulated via the guidewire tube 54.

[0052] When the nosecone 70 is no longer needed, it may be radially folded as shown in Figures 5B and 5C. For example, a pull wire 74 may be connected to a portion of the collapsible structure of the strut 72 in a manner that encourages the nosecone 70 to collapse when it is pulled. Another alternative, shown in Figure 5C, is to mount the proximal end of the nosecone 70 on a concentric tube 76 that is slidable over and relative to the guidewire tube 54, while the distal end of the nosecone is attached to the guidewire tube. Relatively displacing or rotating the telescoping tubes 54, 76 causes the nosecone 70 to collapse. Once the nosecone 70 is folded, it may be retracted within the delivery catheter 26 to free up space in front of the delivery system.

[0053] 6A and 6B illustrate a foldable / invertible nosecone 80 that is collapsible into a folded state with limited or no protrusion from the distal end of the delivery catheter 26. As previously mentioned, the nosecone 80 has an expanded configuration in which it seats on and protrudes distally from the distal end of the delivery catheter 26. Nosecone 80 collapses upon proximal retraction of guidewire tube 54 (or a separate puller wire (not shown) extending through tube 54. Guidewire tube 54 (or puller wire) extends to the distal end of nosecone 80 and pulls the distal end back into the larger body of the nosecone. This transition between the expanded and collapsed configurations may be visualized as like inverting an unfolded umbrella or rubber toilet plunger. That is, nosecone 80 may be formed of an elastomeric material that easily inverts on itself, as in FIG. 6B. Again, once inverted / folded, nosecone 80 simply flattens or rounds and may be advanced out of the way or retracted within delivery catheter 26 proximal to the heart valve.

[0054] With reference to Figures 7A and 7B, a removable nose cone 90 is disclosed. Specifically, the nose cone 90 may be configured similar to a conventional nose cone and seats on the distal end of the delivery catheter 26 with a simple interference fit. A retraction wire 92 that runs along the exterior of the delivery catheter 26 is attached to an anchor point 94 toward the distal end of the nose cone 90. Because the retraction wire 92 is attached only to one side, pulling the wire proximally exerts a lateral force on the nose cone 90, as shown in Figure 7B. The nose cone 90 can then be detached from the distal end of the delivery catheter 26 and withdrawn from the surgical site. To facilitate removal of the disengaged nose cone 90, it may also be configured to fold as described above with respect to Figures 4-6.

[0055] 8A illustrates yet a further alternative nosecone 100 with a retractable sleeve. More specifically, the nosecone 100 is formed by a tubular body 102 terminating at a distal end in a retractable nose 104. For example, the retractable nose 104 may be formed by flap extensions of the tubular body 102 that come together or join almost like a duckbill valve. As shown in FIG. 8B, retracting the tubular body 102 proximally causes the flaps of the retractable nose 104 to separate such that the entire nosecone 100 is pulled proximally over the delivery catheter 26. The nosecone may be formed of two or more separate flaps, or may be formed of a continuous tube shaped with a pointed end.

[0056] FIG. 9 is a radial cross-sectional view taken along line 9-9 of FIG. 3 through a crimped balloon-expandable prosthetic heart valve 40 held within a valve delivery system. As mentioned above, the delivery system may advance both self-expandable and balloon-expandable valves, and FIG. 3 may depict either. The valve 40 is radially crimped to fit within the delivery catheter 26. Within a central lumen through the valve 40 passes an elongated guidewire tube 54 that receives a guidewire 110. An inflation balloon 112 around the guidewire tube 54 is crimped within the prosthetic valve 40. FIG. 9 shows a conventional placement of the guidewire 110, i.e., through the center of the delivery system.

[0057] 10A and 10B are radial cross-sectional views similar to those of FIG. 9, but the guidewire 110 extends along an alternative path that is not centered within the delivery catheter to the distal end of the delivery catheter. For example, the guidewire 110 may be routed through a passage formed within the delivery catheter 26, as shown in FIG. 10A. This leaves the interior of the guidewire tube 54 empty for the passage of fluids or auxiliary instruments. Alternatively, routing the guidewire 110 along the wall of the delivery catheter 26 allows the diameter of the guidewire tube 54 to be reduced, which in turn allows the crimped diameter of the prosthetic valve 40 (and balloon 112, if present) to be reduced. Another possible path for the guidewire 110 is completely outside the delivery catheter 26, as shown in FIG. 10B. Although not shown, the guidewire 110 may be held in a continuous or intermittent tunnel on the exterior of the delivery catheter 26 to avoid separation between them. On the other hand, passing the guidewire 110 along the delivery catheter 26 at a location other than within the central guidewire tube frees up the diameter within the delivery catheter 26 to allow for the use of a guidewire tube for a smaller crimped valve or for other purposes. In one variation, the delivery catheter has a guidewire lumen that extends only along the distal portion of the delivery catheter. This arrangement may facilitate easier set-up since the entire delivery catheter does not have to be advanced over the guidewire.

[0058] 11 is a longitudinal cross-sectional view through an alternative nosecone 114 adapted to provide an angled path for a guidewire 110 routed along a passage within or external to the delivery catheter 26 as shown in FIGS. 10A and 10B. As mentioned, the guidewire 110 extends along the exterior of the delivery catheter 26 until it reaches the nosecone 114, and then angles inwardly through an angled channel 115 into a central bore 116 of the nosecone. The same distal path for the guidewire 110 may be provided in the embodiment of FIG. 10A, where the guidewire extends through a longitudinal passage within the wall of the delivery catheter 26. Again, this frees up space within the central tube 54 for other uses, or the tube 54 may be reduced in size, thereby allowing for a reduction in the overall size of the delivery catheter 26.

[0059] 12A and 12B are schematic diagrams of the distal end of delivery catheter 26 showing a further alternative nose cone 118 in extended and collapsed states. As explained, for procedures on the tricuspid annulus, as shown in FIG. 1A, a tapered nose cone or tip is typically not required because catheter 26 does not traverse the atrial septal puncture. Although a tapered tip aids in the insertion of delivery catheter 26 into the groin (i.e., to access the femoral vein), it presents too large an obstacle once the delivery system passes through the tricuspid valve and into the right ventricle.

[0060] As a solution to this dilemma, a foldable nose cone 118 surrounded by a flexible covering 118a may be provided on the distal end of the delivery catheter 26. The nose cone 118 may be comprised of a series of connected nested layers of a stack, a "layer cake," which is biased or temporarily held in the tapered shape shown in FIG. 12A, but can be folded back on itself by retracting a pull wire or inner tube, for example, as shown in FIG. 12B. For example, the inner tube 54 shown in FIGS. 6A and 6B may be used. The smaller layers nest within the larger layers, and the flexible covering 118a retracts with the nose cone 118. After folding, the nose cone 118 may be temporarily advanced beyond the distal tip of the catheter 26 to allow passage of the expandable heart valve or other instruments used in its implantation.

[0061] 13A and 13B show the distal end of the delivery catheter 26 and still further foldable nose cone 119 in both extended and folded states. In this embodiment, the nose cone 119 has layers that are nested in an angular manner and may be folded by rotating or retracting the pull wire, as shown in FIG. 13B. Again, the flexible covering 119a provides a smooth tapered exterior to facilitate introduction into, for example, the groin area and femoral vein. After folding, the nose cone 119 may also be temporarily advanced beyond the distal tip of the catheter 26 to allow for the passage of the expandable heart valve or other instruments used in its implantation.

[0062] Inflatable System 14 is a longitudinal section through an inflatable nosecone 120 carried on the end of a central tube 122, which may be a guidewire tube. The central tube 122 continues through the middle of the nosecone 120 and has one or more side ports 124 that are open to an inner lumen 126. A distal seal 128 provides a fluid closure at the distal end of the lumen 126.

[0063] 15A and 15B are close-up views of the distal end of the inflatable nosecone 120 illustrating an alternative use of a distal seal 128. FIG. 15A illustrates what may be referred to as a zero seal, meaning an annular seal 128 that closes on itself to seal the distal end of the lumen 126 in the absence of an instrument passing through the seal. The presence of the zero seal 128 allows the lumen 126 of the central tube 122 to be pressurized with an insufflation fluid for use in a variety of situations. For example, the nosecone 120 itself may be inflatable and may be formed by an outer wall 130 that surrounds an inner inflation space 132. Because the nosecone 120 in the illustrated embodiment surrounds the central tube 122, the inner inflation space 132 is a circle in radial cross section.

[0064] 15B illustrates a guidewire 136 that may be passed through an annular zero seal 128. The seal 128 is preferably elastomeric and bends outward upon passage of the guidewire 136, but provides a good fluid seal therearound for pressurization and continued use of the lumen 126. The zero seal 128 is shown with a conical inner wall 134 that facilitates passage of the guidewire 136.

[0065] FIG. 16A is an enlarged view of the distal end of nose cone 140 showing an alternative distal seal 142 positioned at the distal end of inner lumen 143, and FIG. 16B shows the passage of a guidewire 144 through the seal. Nosecone 140 is preferably solid, but may also be inflatable as described above with respect to FIGS. 14-15. Distal seal 142 is formed as a duckbill type seal, having two elastomeric flaps 145 that come together along the central axis of inner lumen 143 and angled proximally. Thus, pressure within lumen 143 tends to close the two elastomeric flaps 145, thus better allowing for pressurization of inner lumen 143. FIG. 16C shows the addition of a lead-in seal 146 proximally from duckbill seal 142, facilitating the passage of guidewire 144 through the duckbill seal. That is, the lead-in seal 146 is conical and tapers toward a central axis so that the guidewire 144 can be threaded between the flaps 145 of the duckbill seal 142 .

[0066] FIG. 17 is a schematic diagram of a system 150 for providing fluid to a valve delivery guidewire tube that doubles as an inflation tube, as described herein. The valve delivery system may incorporate a nosecone 140 having a distal seal 142, as described with reference to FIGS. 16A-16C. An elongated guidewire 144 extends throughout the valve delivery system, including a delivery catheter 152 attached to a proximal handle 154. The guidewire 154 passes through a proximal seal 158 on the handle 154 and then extends the length of the system through the distal seal 142. An inner lumen within the delivery catheter 152, such as the inner lumen 143 described above, can then be pressurized with inflation fluid. For example, an angled side port 160 diverging from the proximal handle 154 may be in fluid communication with the inner inflation lumen, and may also be in fluid communication with a flexible hose 162 attached to a source of pressurized fluid, such as a manual syringe 164. The pressurized fluid may be, for example, saline so that the inner inflation lumen can be supplied with pressurized saline as desired.

[0067] 18A and 18B are longitudinal cross-sectional views of yet a further nosecone 170 having a solid body 172 that fits onto the distal end of a delivery catheter 174. An outer balloon 176 surrounding the solid body 172 may be inflated and deflated via an inner inflation lumen 177 that opens to a side port 178. A distal seal 180 provided at the distal end of the inflation lumen 177 allows for its pressurization. The inflated balloon 176 may be useful for navigating through intricate and potentially fragile anatomy, such as through native heart valves and into ventricles with chordae tendineae.

[0068] FIG 19 is a longitudinal cross-sectional view through a distal section of a valve delivery system 190 shown to illustrate one possible use of a dual guidewire / inflation tube 192. A portion of the crimped valve has been removed to illustrate the dual guidewire / inflation tube 192 having one or more side ports 194 therein. A valve expansion balloon 196 surrounds the tube 192 and has an interior space open to the one or more side ports 194. FIG 20 illustrates the expansion of the balloon 196 within an expandable prosthetic heart valve 198, such as similar to the one shown implanted in the sequence of FIGS. 2A-2C.

[0069] septal stabilizer 21 is a longitudinal cross-sectional view through the distal section of a valve delivery system 200 designed to facilitate passage through the septal wall in the heart. The system 200 has a distal nosecone 202 attached to the distal end of a delivery catheter 204. A crimped prosthetic heart valve 206 resides within the catheter 204. An inner tube, such as an inner guidewire tube 208, extends the length of the system and through the valve 206 and is attached within the nosecone 202, through which a guidewire 210 may pass. The inner guidewire tube 208 has one or more side ports 211 that open to the interior space of a septal stabilization balloon 212.

[0070] 22A-22C are cross-sections of the heart illustrating a series of steps in deploying the septal stabilization balloon 212 of FIG. 21 during mitral valve replacement. A puncture is made into the septal wall SW, through which a guidewire sheath (not shown) and then guidewire 210 are introduced. Once the guidewire 210 has passed through the septal wall SW, the guidewire sheath is removed and the distal end assumes an atraumatic coiled shape as shown. The delivery catheter 204 is then advanced through the vessel along the guidewire 210 until the nosecone 202 has traversed the septal wall SW.

[0071] At this point, as shown in FIG. 22B, the nosecone 202 is held stationary and the catheter 204 is retracted. The septal stabilization balloon 212 remains in place within the puncture through the septal wall SW. Positioning of the balloon 212 within the puncture through the septal wall SW may be aided by the use of fluoroscopy or other such visualization means. The septal stabilization balloon 212 is then inflated to the shape shown in FIG. 22C. That is, the septal balloon 212 defines a spool or hourglass shape with a central circular groove 214 that receives the septal wall SW and a pair of annular lobes 216 that flank the septal wall SW.

[0072] The central through hole 218 provides a passageway for subsequent advancement of the delivery catheter 204 and replacement of the mitral valve. Thus, the septal stabilization balloon 212 provides a barrier between the delivery system, including the catheter 204, and the septal anatomy so as to distribute the load of steering insertion over a larger surface area and reduce concentrated local forces and the risk of pinching. Additionally, the balloon 212 creates support for the delivery system by stiffening the septal wall SW during the valve replacement procedure.

[0073] Guidewire hardening 23 illustrates an exemplary convertible guidewire 220 having a portion that may be hardened as desired. Typically, the guidewire is made of stainless steel and is relatively flexible. However, in heart valve replacement procedures, conventional flexible guidewires may be insufficient to guide a delivery catheter into position across the native valve annulus, for example, for atrioventricular valve replacement, as described herein. More specifically, as a delivery catheter advances over a flexible guidewire positioned within the ventricle, the stiffness of the catheter and associated components tends to overcome the minimal stiffness of the guidewire and pull the guidewire out of position.

[0074] As a proposed solution, Figure 23 shows a convertible guidewire 220 having an inner core wire 222 surrounded by a coil wire 224 extending along its length. Both the core wire 222 and the coil wire 224 are electrically conductive and are placed in electrical communication at their distal ends. The coil wire 224 has an insulating coating on its exterior to avoid shorting the circuit. A power source 226 is shown diagrammatically providing electrical current to the circuit.

[0075] The core wire 222 has a bimetallic configuration, i.e., is made of Nitinol with sections of different austenite finish temperatures (Af) to create distinct sections of stiffness within the guidewire, if desired. For purposes of definition, austenite is the high temperature parent phase of Nitinol alloys having a B2 crystal structure, while martensite is the lowest temperature phase of Nitinol shape memory alloys having a B19' (B19 prime) monoclinic crystal structure. The austenite finish temperature (Af) is the temperature at which the transformation from martensite (or R-phase) to austenite is complete upon heating of the alloy. Nitinol remains highly flexible in the martensite phase and then stiffens as it returns to its memory shape or transitions to the austenite phase.

[0076] In the illustrated embodiment, core wire 222 is treated to have at least one section 228 of different Af temperatures by virtue of heat setting the wire differently in different zones. Specifically, section 228 is heat treated to have a higher Af temperature than the remainder of core 222. Due to the higher core Af temperature, the wire in section 228 is flexible below body temperature (the NiTi core is shape memory / martensite). If desired, core wire section 228 transforms into a stiff member via an induced current applied to the coil (i.e., the NiTi core is superelastomeric / austenite when current is applied to the coil).

[0077] In this manner, the majority of core wire 222 may remain flexible at body temperature, while certain sections, such as section 228, may be hardened upon application of an electrically induced current and thus heating of guidewire 220. In particular, transformable section 228 near the coil distal end of guidewire 220 may be selectively hardened. In one example, transformable section 228 is heat treated such that its Af temperature is greater than body temperature (approximately 37° C.), such as 60° C.

[0078] 24A-24C illustrate a sequence of uses of the convertible guidewire 220 of FIG. 23. First, a puncture is made in the septal wall SW through which a guidewire sheath (not shown) and then guidewire 220 are introduced. The guidewire sheath is directed down through the mitral valve into the left ventricle and then removed so that the distal end of guidewire 220 assumes an atraumatic coil shape as shown. At this stage, no current is applied to guidewire 220, which remains quite flexible. If delivery catheter 230 were advanced across the septal wall SW to enter the left ventricle, the stiffness of the catheter would cause guidewire 220 to be pulled back up into the left atrium.

[0079] Instead, an electrical current is applied to guidewire 220, which stiffens transformable section 228. This allows a delivery catheter 230 to be advanced along guidewire 220 across the septal wall SW and into the left ventricle, as shown in Figures 24B and 24C. Once delivery catheter 230 has crossed the mitral valve, the electrical current in guidewire 220 can be removed such that the guidewire assumes its fully flexible properties as before.

[0080] Convertible / Compressible Access Sheath FIG. 25 is a schematic diagram of a transvascular method of introducing a flexible catheter assembly 240, 242 into the heart to perform a procedure, illustrating the tortuous vasculature pathway that presents a challenge to the procedure. The catheter assembly includes a catheter access sheath 240 and a concentric catheter 242 extending from the distal end of the sheath. The assembly is shown during the initial stages of introduction into the body for an intracardiac procedure, with the access sheath 240 inserted into the vein through an incision and a portion of the catheter 242 visibly extending from the sheath. Often, the venous system from the femoral vein up towards the ascending aorta is relatively tortuous as shown, requiring a great deal of flexibility in the catheter assemblies 240, 242. However, both the access sheath 240 and the expandable catheter 242 require a minimum amount of axial stiffness to allow the surgeon to advance the components through the vasculature. The conflict between flexibility and stiffness creates a tradeoff.

[0081] Additionally, the delivery system profile for transcatheter mitral and tricuspid valve replacement catheters 242 requires a large ID (>30 Fr or 10 mm). This can pose a challenge for access, especially if an additional sheath 240 is required to gain access, thereby adding additional profile on top of the delivery system, pushing >33 Fr (11 mm) and above. Currently, there are no large diameter sheaths 240 available to gain access for devices over 26 Fr (the GORE® DrySeal Flex Introducer Sheath is the largest known commercially available sheath with a maximum ID of 26 Fr). Therefore, a low profile sheath solution for access would be highly beneficial.

[0082] 26 is a diagram of the entire valve delivery system 250 illustrating the relative movement between the control handle 252 and the inner catheter 254 riding over the guidewire 256 relative to the access sheath 258. In one typical procedure, the surgeon or technician holds a portion of the access sheath 258 steady while advancing the control handle 252 and the catheter 254 distally. Because the access sheath 258 conforms to tortuous anatomy, it can be difficult to advance the catheter 254 if it is bent in multiple places. However, the access sheath 258 must have a certain amount of flexibility to navigate tortuous anatomy. Thus, the access sheath 258 is configured to be transformed from a more flexible configuration to a stiffer configuration as described.

[0083] FIG. 27 illustrates a convertible access sheath 258 for use in the system of FIG. 26 having an expandable stiffening helix thereon. More specifically, the access sheath 258 comprises an elongated flexible tube 260 extending distally from a proximal hub 262. The hub 262 preferably has one or more valves for sealing around the inner catheter 254 which slides through the tube 260. A narrow expandable filament 264 is helically disposed from the hub 262 around the elongated tube 260 along at least a majority of the tube, and potentially the entire length of the tube. There may be one or more filaments 264 helically surrounding the tube 260. Although not shown, an external tubular covering may be provided around the filament 264 to maintain a smooth outer surface for the sheath 258. A fill valve 266, which may be provided on the hub 262, supplies infusion fluid (saline, air, or any fluid medium) to the expandable filament 264.

[0084] 28A-28C are radial cross-sectional views showing alternative configurations of the convertible access sheath 258. In FIG. 28A, the elongated tube 260 is shown with a typical cross-sectional shape as shown in the body when the filament 264 is contracted. That is, the tube 260 has sufficient radial integrity to remain somewhat circular, and the entire access sheath 258 remains relatively flexible to pass through tortuous anatomical structures. In contrast, FIG. 28B shows the filament 264 expanded with a fluid, which tends to stiffen the entire sheath 258 and helps maintain the tube 260 in a circular cross-sectional shape. Thus, the access sheath can be made alternately more or less flexible depending on whether the filament 264 is filled with a fluid or not, to reduce the effect. FIG. 28C illustrates a slightly modified version of the access sheath 258, in which the flexible tube 260 is formed with pleats or longitudinal folds so that it is somewhat radially collapsible. Thereafter, injecting fluid into filament 264 expands tube 260 into a circular configuration, as shown in FIG. 28B.

[0085] Typically, the sheath support structure is a metal coil and / or braid to maintain hoop strength and provide resistance to kinking, but these are static (constructed to one diameter) and still have a tendency to kink / buckle. The expandable support structure, the filament 264, can provide temporary support when needed and then contracted when not. The advantage here is that when contracted, it takes on a smaller profile shape upon introduction and can then be expanded to its intended diameter to allow passage of the catheter 242. Furthermore, because the sheath 258 is non-metallic, it can be contracted and peeled back (or "squished" back), for example, if the sheath is only desired for access and the physician wishes to remove it. This has advantages when it is desired to provide a long access sheath, especially for passing through tortuous veins, and then pulled back on the device for the remainder of the procedure.

[0086] 29 is a schematic diagram of the proximal end of convertible access sheath 258 illustrating the capability of axial compression. That is, when filament 264 is contracted, the entire sheath 58 may be axially compressed in an accordion-like fashion. Such a result may be facilitated by providing circumferential pleats or other such foldable structures within tube 260.

[0087] Another problem with access sheaths that use metal coils or braids is that the length of the sheath is generally fixed. Although it may be desirable to utilize a long sheath to pass certain anatomical landmarks, the sheath is only required for catheter introduction. With a long sheath, the surgeon may not be able to fully withdraw the sheath, which may inhibit movement of the system's components.

[0088] FIG. 30 is an elevational view of an alternative compressible access device 270 in an extended configuration, and FIG. 30A is an enlarged view of a portion thereof. The sheath 270 may consist of a proximal hub 272 having an elongated sheath 274 extending distally therefrom. The wall structure of the elongated sheath 274 allows for axial compression from the extended configuration to the axially collapsed configuration. Specifically, the elongated sheath 274 may be formed by an inner liner, an axially compressible support structure, and an outer jacket for the introducer sheath. In the illustrated embodiment, the sheath 274 comprises an outer jacket 276 that surrounds a series of axially spaced rings 278 joined together by axially compressible struts 280. The axially compressible support structure comprising the rings 278 joined by struts 280 may be formed by a laser cut hypotube pattern having a series of compressible sections. The struts 280 are shown in a serpentine configuration, allowing for axial collapse. Rather than a continuous coil, this shows a particular pattern that allows for compression of the inner struts 280 that link the radial support rings 278. In the illustrated embodiment, there are four pairs of struts 280 that extend between adjacent rings 278, with the pair of struts between two rings being rotationally offset from the pair of struts between the next two rings. Of course, the number and arrangement of struts 280 can be varied. Although the entire sheath 274 is shown constructed in a compressible manner, the compressible portion is limited to only a section of it, for example the middle section.

[0089] Figure 31 is an elevational view of the compressible access sheath of Figure 30, illustrating its axial compression. Specifically, the expanded length L1 as shown in Figure 30 may be reduced to a compressed length L2 as shown in Figure 31. The compressed length L2 may be 30-70% of the expanded length L1.

[0090] Finally, Figures 32A and 32B are close-up views of several links in an alternative compressible access sheath having wall structures that allow for an extended configuration and an axially compressed configuration, respectively. As previously described, the sheath comprises an outer jacket 276 that surrounds a series of axially spaced rings 278 joined by axially compressible struts 282. In this embodiment, the struts 282 are formed in a zigzag configuration rather than a serpentine. Between every two rings 278 there are individual struts 282 distributed at 90 degree angles. Again, the four struts 282 between two of the rings 278 may be rotationally offset relative to the four struts between the next two rings.

[0091] Removable Access Sheath Tip FIG. 33 is a diagram of the entire valve delivery system 320 illustrating the forward movement of the control handle 322 and inner catheter 324 along with the access sheath 328 over the guidewire 326. In one typical procedure, the surgeon or technician holds a portion of the access sheath 328 steady while advancing the control handle 322 and catheter 324 distally. Prior to distal displacement of the catheter 324 and implantation of the prosthetic valve carried therein, the access sheath 328 is inserted into the patient's vasculature. While positioning the delivery system 320 for a tricuspid valve procedure, there needs to be sufficient clearance between its distal tip and the right ventricle to ensure proper positioning, particularly depth control. A tapered tip on the distal end of the delivery catheter 324 is beneficial for gaining access to the vasculature, but such a tapered tip reduces the maneuvering space within the right ventricle.

[0092] As a result, Figures 33 and 34 illustrate the distal end of the access sheath 328 having a breakaway delivery system tip 330 incorporated thereon. Figure 35 shows the breakaway delivery system tip 330 and Figures 36A-36B show the distal displacement of the delivery catheter 324 therethrough. The breakaway tip 330 comprises a flexible tubular bag or "shaft" 332 having O-ring style seals 334, 336 at its distal and proximal ends. The distal and proximal seals 334, 336 are sized to provide a hemostatic barrier around the access sheath 328 and delivery catheter 324. A tapered distal end 338 extends around the distal end of the delivery catheter 324 to provide an atraumatic forward end for introduction into the vasculature and thereafter through the vasculature to the tricuspid annulus. The tapered distal end 338 may be formed by a pair of leaves or petals that come together at a point but can be bent apart upon passage of the delivery catheter 324. The leaves or petals of the distal end 338 have sufficient stiffness to provide a hemostatic seal within the access sheath 328 and / or an atraumatic tapered tip for entry of the delivery catheter 324 through an incision into the body.

[0093] FIG. 34A shows an alternative in which the breakaway delivery system tip 330' forms the access sheath itself. That is, a flexible tubular bag or "shaft" 332 with O-ring style seals 334, 336 at the distal and proximal ends fits directly around the catheter 324 to provide a hemostatic sheath as the catheter is introduced into the body. Delivery catheter 324 and delivery system tip 330' for delivery system 320. The distal seal 334 and tapered distal end 338 are carried forward by the catheter 324 as it advances through the incision, thus providing an atraumatic entry. At the point where the flexible access bag 332 extends to its full length, and potentially when a pair of outer wings or flanges 340 contact the exterior of the patient's access site, the movement of the access bag 332 is stopped. The tip of the catheter 324 is then advanced through and beyond the petals of the distal end 338 and delivery and deployment of the heart valve can proceed without the extended tip 338 .

[0094] FIG. 36A shows distal advancement of the delivery catheter 324. Initially, a friction fit between the distal seal 334 and the delivery catheter 324 carries the tapered distal tip 338 forward with the catheter. The surrounding flexible shaft 332 provides a hemostatic barrier around the delivery system 320, whether it be the access sheath 328 and catheter 324, or just the catheter 324 as in FIG. 34A. The overall length of the breakaway tip 330 is less than the length required to advance the delivery system 320 to the tricuspid annulus, and at some point, a pair of outer wings or flanges 340 stop further advancement of the tip 330. The flanges 340, which may also comprise an annular flange, contact the exterior of the patient's access site, stopping the movement of the tip 330. Next, FIG. 36B shows continued distal advancement of the delivery catheter 324 through the flexible leaves or petals of the distal tip 338. This removes the tapered end from the access sheath 328 before reaching the tricuspid annulus, thus reducing the distal profile of the delivery system and improving maneuverability. The distal seal 334 maintains hemostasis around the delivery catheter 324.

[0095] The breakaway tip 330 is manufactured using known biocompatible materials. Movement of the delivery catheter 324 through the leaves or petals of the distal end 338 is entirely passive, depending solely on the relative lengths of the tip and sheath. The leaves or petals of the distal end 338 may be sufficiently stiff to provide a tapered entry tip, but may also be sufficiently flexible to allow the delivery catheter 324 to bend them apart. Alternatively, the leaves or petals may be hinged to an O-ring seal 334 at their proximal ends. The material of the tubular bag or shaft 332 may be similar to flexible liners used to protect surgical incision sites.

[0096] Steerable Catheter Multi-planar movement of the catheter through multiple puller wires allows the user to steer the catheter through tortuous vasculature and to the proper implant location. Often, when a multi-function catheter system as used herein is activated to deliver a heart valve, activation of a first feature changes or alters the performance or direction of a second feature. For example, when a user activates a secondary bend, it may change the direction in which the primary bend moves. This requires the user to mentally and / or manually compensate for the new movement, which can be difficult. As a result, the present application contemplates a steerable catheter capable of multi-planar movement through multiple puller wires controlled by a motor and controller that automatically detects the movement (bend, rotate, advance, etc.) of any one feature in the catheter through sensors in the system and adjusts the control to maintain the desired output of the remaining features.

[0097] As shown in FIG. 37, an embodiment of a steerable delivery catheter 350 may be used to deploy an implant, such as a prosthetic replacement heart valve, to a location within a patient's body. In some embodiments, the delivery catheter 350 may provide multiple planes of deflection (e.g., two or more planes) to aid in navigation through the patient's blood vessels and for improved precision during delivery of the implant. Although the delivery catheter 350 may be described in certain embodiments in connection with a percutaneous delivery approach, and more specifically a transfemoral delivery approach, it should be understood that the features of the delivery catheter 350 may be applied to other delivery systems, including delivery systems for transapical, transatrial, or transjugular delivery approaches. The delivery catheter 350 is disclosed in U.S. Patent Application Publication No. 2021 / 0145576 to Becerra and is expressly disclosed herein.

[0098] The delivery catheter 350 includes an elongate shaft 352 having a proximal end 354 and a distal end 356, with a housing in the form of a handle 360 ​​coupled to the proximal end. The elongate shaft 352 may be used to hold the implant for its advancement through the vasculature to a treatment location. The elongate shaft 352 may further include a relatively rigid live-on (or one-piece) sheath 362 surrounding an interior portion of the shaft 352, which may reduce undesired movement of the interior portion of the shaft 352. The live-on sheath 362 may be attached to the proximal end of the shaft 352 proximal to the handle 360, for example, to a sheath hub.

[0099] FIG. 37A shows an embodiment of a catheter distal end 356 that includes a rail hypotube 370 (distal end toward the left). The rail hypotube 370 contains several circumferential slots and can generally be divided into several different sections. At the proximal end is an uncut (or unslotted) hypotube section 372. Moving distally, the next section is a proximal slotted hypotube section 374 that includes several circumferential slots cut into the rail hypotube 370. Generally, a series of two diametrically opposed slots are cut around axially spaced circumferential locations, forming approximately half of the circumference. Thus, two diametrically opposed backbones are formed between the slots that extend up the length of the hypotube 370, and the slotted hypotube section 374 may be bent in a longitudinal plane 376. Thus, the proximal hypotube section 374 can be guided by the proximal puller wire 380 (see FIGS. 38-39). Moving further distal from the slotted section 374 is the anchor segment 378 where the proximal puller wire 380 is connected, so the slot can be avoided.

[0100] Following distally from the proximal pull wire anchor segment 378 is a similarly formed distal slotted hypotube section 382. At the most distal end of the distal slotted hypotube section 382 is a distal pull wire connection area 384, which is again a non-slotted section of the rail hypotube 370. Thus, the distal slotted hypotube section 382 can be guided by the distal pull wire 381 (see FIGS. 38-39). The distal slotted hypotube section 382 is similar to the proximal slotted hypotube section 374, but has more slots cut out at a comparable length, thus providing easier bending in the longitudinal plane 386 than the proximal slotted hypotube section 374. In some embodiments, the proximal slotted section 374 can be configured to undergo a bend of approximately 90 degrees with a half inch radius, while the distal slotted section 235 can bend approximately 180 degrees within a half inch.

[0101] The spine of the distal slotted hypotube section 382 is offset from the spine of the proximal slotted hypotube section 374. Thus, the two sections achieve different bending patterns, allowing three-dimensional steering of the catheter distal end 356 in conjunction with axial rotation of the elongate shaft 352. In some embodiments, the spine can be offset 30 degrees, 45 degrees, or 90 degrees as shown by bending planes 378, 386, although the particular offset is not limiting. In some embodiments, the proximal slotted hypotube section 374 can include a compression coil. This allows the proximal slotted hypotube section 374 to retain rigidity for a particular bend of the distal slotted hypotube section 382.

[0102] The handle 360 ​​includes a controller 390 configured to control at least one motor. The controller 390 shown may include a number of control buttons and may be located on the handle 360 ​​as shown or may be located remotely.

[0103] 38 illustrates a cross section of the handle 360 ​​including a motor 392 that may be utilized to actuate the pull wire during advancement through the vasculature. The motor may also be used to actuate the shaft / sheath to deploy and release the implant at the treatment site.

[0104] The controller 390 is configured to control the operation of the motor 392 and may include input devices and output devices (marked as items 394) as shown in FIG. 38. The controller 390 may also include a memory 396, a processor 398, and a power source 400. The input devices and output devices 394 may have multiple configurations, including electrical ports or terminals configured to transmit electrical signals. The input devices may be configured to receive signals from the motor 392 and also from sensors positioned on the delivery system 350. The output devices may be configured to transmit signals to the motor 392 or other components of the system 350 that may be received from the processor 398 or other components of the system 350. In certain embodiments, the input devices and output devices 394 may include wireless transmitting devices, such as Wi-Fi or Bluetooth devices, or other devices configured for wireless communication. In embodiments in which the controller 390 is located remotely from the delivery device, the input devices and output devices 394 may be configured to transmit and receive information via the Internet or other forms of communication media.

[0105] Thus, the motorized puller wires 380, 381 enable an automated bending solution for the delivery catheter 350. Sensors in the handle 360 ​​and / or shaft 352 may detect the bending, rotation, and orientation angles. The processor 398 can then calculate the position of the catheter tip and correct or compensate for subsequent movements. At a minimum, the processor 398 can adapt to accommodate the effect of multiple directional puller wires working at once to provide proper catheter positioning.

[0106] Position Sensors 40 and 41 illustrate the use of a catheter positioning sensor 420 deployed adjacent to a target tricuspid annulus. During implantation of a prosthetic tricuspid valve, positioning of the delivery catheter 26 within the annulus is important to ensure that the valve is in the correct location during deployment. Current technology utilizes echocardiography and fluoroscopy to view the position of the delivery system relative to the annulus, but imaging can be difficult due to patient anatomy and image quality. Poor imaging during the procedure can cause delays and potentially malpositioning of the delivery system, resulting in a failed implant.

[0107] As a result, the catheter positioning sensor 420 utilized in cooperation with the delivery catheter 26 provides real-time data at the annulus within the patient's heart to provide an accurate reading of the location of the distal tip of the delivery catheter 26 to complement imaging and improve positioning. The catheter positioning sensor 420 comprises a small data node catheter (2-3 French) inserted along the delivery catheter 26 into the tricuspid annulus. As shown in Figures 40 and 41, the node catheter goes along the inner edge of the patient's right atrium and is positioned on the atrial surface of the patient's annulus. The distal end can have a single node point radiator 422, or an adjustable ring radiator (shown in dashed lines) to better conform to the annulus.

[0108] Once in position, the catheter positioning sensor 420 emits an RF field or other suitable electromagnetic frequency that would not affect echocardiography or fluoroscopy procedures or the patient's anatomy. The dashed line 424 shows one such RF field across the atrial side of the tricuspid annulus. On the distal end of the delivery catheter 26, in line with where positioning of the valve implant is important during deployment, the sensor 426 is positioned to be seen by the emitter 422. The relative position of the delivery system tip sensor 426 to the emitter 422 is converted to xyz distances and output to the user on a display. The coordinates can also be output on a graphical representation of the patient's annulus to help the user visualize the position relative to the anatomy. Additional sensors can be placed on the valve itself, or on other sections of the catheter, and the same data can be read by the catheter sensor to provide more context and additional measurements to the user on the display.

[0109] Valve Frame Access Port Current valve replacement implants pose challenges for future interventions that require crossing the valve. This is particularly difficult with permanent devices such as pacemaker leads, which would be forced to be placed through the leaflets of the new prosthetic valve without providing an alternative pathway.

[0110] As a result, the present application contemplates the implantation of a modified prosthetic heart valve 430 as shown in Fig. 42, which accommodates the passage of a sensor wire 432, such as a pacemaker lead, that has one or more access ports 434 in the outer body of the valve frame extending axially therethrough, which provides an option for further intervention without compromising the integrity of the prosthetic leaflets.

[0111] 43A and 43B illustrate a modified prosthetic heart valve 430, which in the illustrated embodiment is a modified EVOQUE tricuspid valve made by Edwards Lifesciences Corp. of Irvine, Calif., currently undergoing clinical trials. Among other features, the heart valve 430 has an outer structural frame 436 covered with fabric 438 that surrounds the flexible leaflets of the valve. In the disclosed embodiment, three access ports 434 are evenly distributed around the outer frame and pass through the cover fabric 438 between the struts of the structural frame 436. Although not shown, aligned access ports are provided at the bottom end of the valve 430 so that a sensor lead 432 can be passed straight from proximal to distal or from the atrial side to the ventricular side of the valve.

[0112] Of course, more or less than three sets of aligned access ports 434 may be provided. The small nature of the access ports 434 reduces any backflow that may result, and a fabric flap may also be added to cover the access ports 434 in the event of blood backpressure. Similarly, the access ports 434 may be configured to be normally closed, with the ability to dilate, actuate, or even cut through a marked area to open them up. Additionally, the access ports 434 may have fluorescent or echo marker bands around their perimeter to aid in threading the sensor lead 432 through them.

[0113] While the above is a complete description of the preferred embodiment of the present invention, various alternatives, modifications and equivalents may be used. Moreover, it will be apparent that certain other modifications may be practiced within the scope of the appended claims.

Claims

1. A prosthetic heart valve delivery system, comprising: a flexible access sheath having an internal lumen; a proximal handle; a delivery catheter extending distally from the proximal handle, the delivery catheter having an outer diameter sized to pass through the lumen of the access sheath, the delivery catheter also defining a lumen extending therethrough; an expandable prosthetic heart valve adapted to be crimped and positioned within the lumen of the delivery catheter along a distal end portion of the delivery catheter; a tapered nosecone coupled to and protruding distally from the distal end of the delivery catheter in an extended state, the nosecone configured to facilitate passage of the delivery catheter through a patient's vasculature, the nosecone being formed from a series of nested layers that form a tapered, elongated shape in the extended state and that can be folded longitudinally to a collapsed state to reduce contact with the wall of the heart; an inner catheter extending from the proximal handle, through the lumen of the delivery catheter, and through the prosthetic heart valve, the inner catheter attached to the nosecone; 1. A prosthetic heart valve delivery system comprising:

2. The system described in claim 1, wherein the inner catheter is attached to a distal end portion of the nosecone, and when the inner catheter is pulled, the nosecone transitions to the folded state.

3. The system described in claim 1, wherein the nose cone is surrounded by a flexible cover.

4. The system described in claim 1, wherein the nested layers are biased into the tapered elongated shape.

5. The system described in claim 1, wherein the nose cone can be advanced beyond the distal end of the delivery catheter.

6. The system described in claim 1, wherein the nested layers are nested in an angled manner so as to be foldable by rotating or retracting a pull wire.

7. The system described in claim 6, wherein the nose cone is surrounded by a flexible cover.

8. The system described in claim 1, wherein the flexible access sheath has a wall structure that allows it to be converted from a rigid configuration to a flexible configuration.

9. The system described in claim 1, wherein the flexible access sheath has a wall structure that allows it to be converted from an extended configuration to an axially folded configuration.

10. A prosthetic heart valve delivery system comprising: a flexible access sheath having an internal lumen; a proximal handle; a delivery catheter extending distally from the proximal handle, the delivery catheter having an outer diameter sized to pass through the lumen of the access sheath, the delivery catheter also defining a lumen extending therethrough; an expandable prosthetic heart valve adapted to be crimped and positioned within the lumen of the delivery catheter along a distal end portion of the delivery catheter; a tapered nosecone coupled to and protruding distally from the distal end of the delivery catheter in an extended state, the nosecone configured to facilitate passage of the delivery catheter through the patient's vasculature, the nosecone being collapsible to a collapsed state to reduce contact with a wall of the heart, an inner catheter extending through the nosecone to its distal end, the nosecone configured to invert when the inner catheter is pulled; an inner catheter extending from the proximal handle, through the lumen of the delivery catheter, and through the prosthetic heart valve, the inner catheter attached to the nosecone; 1. A prosthetic heart valve delivery system comprising:

11. The system described in claim 10, wherein the nose cone is formed of an elastomeric material that is reversible to the folded state.

12. The system described in claim 10, wherein the nose cone is flat in the folded state.

13. The system described in claim 10, wherein the nose cone is rounded in the folded state.

14. The system described in claim 10, wherein the flexible access sheath has a wall structure that allows it to be converted from a rigid configuration to a flexible configuration.

15. The system described in claim 10, wherein the flexible access sheath has a wall structure that allows it to be converted from an extended configuration to an axially folded configuration.

16. A prosthetic heart valve delivery system comprising: a proximal handle; an elongate delivery catheter extending distally from the proximal handle, the elongate delivery catheter sized for advancement through a lumen of an access sheath; an expandable prosthetic heart valve adapted to be crimped and positioned along the distal end portion of the delivery catheter; an inner catheter extending through a lumen of the delivery catheter; a nosecone coupled to a distal end portion of the inner catheter; Equipped with the nosecone facilitates passage of the delivery catheter through the patient's vasculature; the nosecone is provided with a series of layers that form a tapered, elongated shape as it advances through the patient's vasculature; At least a portion of the layer is repositionable by manipulating the inner catheter to shorten the length of the nosecone, thereby reducing undesired contact with the wall of the heart.

17. The system described in claim 16, wherein the inner catheter is attached to a distal end portion of the nosecone, and when the inner catheter is pulled, the nosecone transitions to a folded state.

18. The system described in claim 17, wherein the nose cone is surrounded by a flexible cover.

19. The system described in claim 18, wherein the nosecone is formed from a series of stacked, nested layers that form a tapered, elongated shape in an extended state and can be folded longitudinally into a collapsed state to reduce contact with the heart wall.

20. The system described in claim 18, wherein the nose cone is formed from an elastomeric material that is reversible to the folded state.

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