Transcatheter valve delivery system

Abstract

Delivery systems are disclosed herein. According to some embodiments, the present technology includes an actuation element at the proximal portion, an elongate member having a proximal region at the actuation element and a distal region configured to be detachably coupled to an implantable device. The elongate member can include an articulable region at the distal region, a first elongate tube having a flexible region coinciding with the articulable region and a tendon extending longitudinally between the actuation element and the flexible region, and a second elongate tube coaxial with the first elongate tube and fixed to the first elongate tube at one or more locations. Axial movement of the tendon can cause articulation of the articulable region. The delivery system may further include an outer shaft and wherein the elongate member is disposed within the lumen of the outer shaft.

Description

MDT Ref. A0013458W001FortemRef. MDTSH.001WOTRANSCATHETER VALVE DELIVERY SYSTEMCROSS-REFERENCE TO RELATED APPLICATION(S)

[0001] The present application claims the benefit of priority to U.S. Provisional Application No. 63 / 733,212, filed December 12, 2024, and U.S. Provisional Application No.63 / 934,727, filed December 9, 2025, each of which is incorporated by reference herein in its entirety.TECHNICAL FIELD

[0002] The present technology is generally related to transcatheter delivery systems for medical devices, for example, prosthetic heart valves.BACKGROUND

[0003] Patients suffering from various medical conditions or diseases may require surgery to install an implantable medical device. For example, valve regurgitation or stenotic calcification of leaflets of a heart valve may be treated with a heart valve replacement procedure. A traditional surgical valve replacement procedure requires a sternotomy and a cardiopulmonary bypass, which creates significant patient trauma and discomfort. Traditional surgical valve procedures may also require extensive recuperation times and may result in lifethreatening complications.

[0004] One alternative to a traditional surgical valve replacement procedure is delivering implantable medical devices using minimally invasive techniques. For example, a prosthetic heart valve can be percutaneously and transluminally delivered to an implant location. In such methods, the prosthetic heart valve can be compressed or crimped on a delivery catheter for insertion within a patient's vasculature; advanced to the implant location; and re-expanded to be deployed at the implant location. Among devices commonly used to access vascular and other locations within a body and to perform various functions at those locations are medical catheters, or delivery catheters, adapted to deliver and deploy medical devices such as prosthetic heart valves, stent-grafts, and stents to selected targeted sites in the body. Such medical devices typically are releasably carried within a distal region of the delivery catheter in a radially compressed delivery state or configuration as the catheter is navigated to and positioned at a target treatment / deployment site. In many cases, such as thoseMDT Ref. A0013458W001FortemRef. MDTSH.001WO involving cardiovascular vessels, the route to the treatment / deployment site may be tortuous and may present conflicting design considerations requiring compromises between dimensions, flexibilities, material selection, operational controls and the like.

[0005] Typically, advancement of a delivery catheter within a patient is monitored fluoroscopically to enable a clinician to manipulate the catheter to steer and guide its distal end through the patient's vasculature to the target treatment / deployment site. This tracking requires a distal end of the delivery catheter to be able to navigate safely to the target treatment / deployment site through manipulation of a proximal end by the clinician. Such manipulation may encompass pushing, retraction and torque forces or a combination of all three. It is therefore required for the distal end of the delivery catheter to be able to withstand all these forces.

[0006] A delivery catheter desirably will have a low profile / small outer diameter to facilitate navigation through tortuous vasculature; however, small outer diameter catheters present various design difficulties resulting from competing considerations, resulting in design trade-offs. For instance, such delivery catheters must be flexible enough to navigate the tortuous vasculature or anatomy of a patient. However, typical constructions of delivery catheters must attempt to balance a requisite flexibility, with axial strength / stiffness (the property that permits the delivery catheter to be pushed and pulled) and torsional strength / stiffness (the property that permits the delivery catheter to be rotated about its longitudinal axis). It is especially important to balance these properties in a distal portion of the delivery catheter within which a prosthesis is held in its radially compressed, delivery state.

[0007] A need in the art still generally exists for improved systems for navigating through or within a patient's anatomy.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Instead, emphasis is placed on illustrating clearly the principles of the present disclosure.

[0009] FIG. 1 A is a perspective view of a delivery system in accordance with several embodiments of the present technology.

[0010] FIG. IB is a side view of a portion of a delivery system in accordance with several embodiments of the present technology.MDT Ref. A0013458W001FortemRef. MDTSH.001WO

[0011] FIG. 1C is a side view of the portion of the delivery system of FIG. IB with the capsule partially withdrawn, in accordance with several embodiments of the present technology.

[0012] FIG. 2 depicts an illustration of the delivery system of FIGS. 1 A and IB during partial deployment of a prosthesis, in accordance with several embodiments of the present technology.

[0013] FIGS. 3A and 3B depict illustrations of different enlarged views of the distal end and delivery catheter of the delivery system of FIGS. 1 A and IB in accordance with several embodiments of the present technology.

[0014] FIG. 3C depicts an axial cross-sectional view taken along line 3C-3C in FIG.1C.

[0015] FIG. 4 depicts a side view of an actuation element for use with the delivery systems of the present technology.

[0016] FIGS. 5 A and 5B depict illustrations of a prosthetic heart valve that may be used with the delivery systems disclosed herein in accordance with several embodiments of the present technology.

[0017] FIG. 6A is a perspective view of a multilayer elongate shaft in accordance with several embodiments of the present technology.

[0018] FIG. 6B shows the delivery system of FIG. 6A positioned within the aorta in accordance with several embodiments of the present technology.

[0019] FIG. 7 is an exploded view of the ML shaft of FIG. 6A in accordance with several embodiments of the present technology.

[0020] FIG. 8 is an elongated member having helical tendons in accordance with several embodiments of the present technology.

[0021] FIG. 9A shows an enlarged view of a distal portion of a delivery system incorporating the ML shaft of FIG. 6 A, in accordance with several embodiments of the present technology.

[0022] FIG. 9B shows a partial exploded view of the proximal portion of the ML shaft of FIG. 6A, along with a control interface, in accordance with several embodiments of the present technology.MDT Ref. A0013458W001FortemRef. MDTSH.OOIWO

[0023] FIGS. 9C and 9D show a control interface in an unlocked and locked position, respectively, in accordance with several embodiments of the present technology.

[0024] FIG. 10 shows a portion of an example actuation element in accordance with several embodiments of the present technology.

[0025] FIG. 11 is an axial view of a knob of the actuation element shown in FIG. 10, in accordance with several embodiments of the present technology.

[0026] FIG. 12 is an exploded view of an ML shaft in accordance with several embodiments of the present technology.

[0027] FIG. 13A is a side view of the ML shaft of FIG. 12 in a curved state in accordance with several embodiments of the present technology.

[0028] FIGS. 13B and 13C are axial cross-sectional views of the ML shaft of FIG. 13A taken along lines 13B-13B and 13C-13C, respectively, in accordance with several embodiments of the present technology.

[0029] FIG. 14 shows a delivery system positioned within the aorta in accordance with several embodiments of the present technology.

[0030] FIGS. 15A and 15B depict a delivery system having an articulating middle shaft deployed within a model aorta and aortic valve in two different rotational positions, according to several embodiments of the present technology.

[0031] FIGS. 16A-16D depict a delivery system having an articulating middle shaft during various stages of deploying a prosthetic valve, in accordance with several embodiments of the present technology.

[0032] FIGS. 17A and 17B depict a delivery system without an articulating middle shaft being deployed at various stages in a model, in accordance with several embodiments of the present technology.

[0033] FIGS. 18A and 18B depict a delivery system with an articulating middle shaft being deployed at various stages in a model, in accordance with several embodiments of the present technology.DETAILED DESCRIPTION

[0034] Specific embodiments of the present disclosure are now described with reference to the figures. The following detailed description describes examples of embodimentsMDT Ref. A0013458W001FortemRef. MDTSH.001WO and is not intended to limit the present technology or the application and uses of the present technology. Although the description of embodiments hereof is in the context of a delivery system, the present technology may also be used in other devices. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description.

[0035] The terms “distal” and “proximal”, when used in the following description to refer to a delivery system or catheter are with respect to a position or direction relative to the treating clinician. Thus, "distal" and "distally" refer to positions distant from, or in a direction away from the treating clinician, and the terms "proximal" and "proximally" refer to positions near, or in a direction toward the clinician.I. Example Delivery Systems

[0036] FIGS. 1 A-1C illustrate an example of a delivery system 100 in accordance with several embodiments of the present technology. One skilled in the art will realize that FIGS.1A-1C illustrate one example of a delivery system and that existing components illustrated in FIGS. 1A-1C may be removed and / or additional components may be added to the delivery system 100.

[0037] As shown in FIG. 1A, the delivery system 100 generally comprises a catheter portion 102, a distal portion 104, and an actuation element 106 by which the distal portion 104 is effectively controlled. In some embodiments, for example as shown in FIG. 1 A, the actuation element 106 comprises a handle. In other embodiments, the actuation element 106 may comprise an interface for coupling the delivery system 100 to an actuating cradle, or a robotic system for automated control of the delivery system 100. The delivery system 100 may also include an introducer 107 that is configured to slide over at least a portion of the catheter portion 102. The catheter portion 102 may be of a length and size so as to permit a controlled delivery of the distal portion 104 to a desired implantation location, for example, a patient's heart. The distal portion 104 provides the means by which an implantable medical device, e.g., a prosthetic heart valve or stent graft, or therapeutic payload can be mounted for delivery to the implantation location and further provides for or allows the expansion of the implantable medical device for effective deployment thereof. The introducer 107 operates to provide an access lumen for introduction of the catheter portion 102 and the distal portion 104 (including the implantable medical device) into a patient's body. The actuation element 106 is configured to control movements as translated to the distal portion 104 by way of the elongate structure ofMDT Ref. A0013458W001FortemRef. MDTSH.001WO the catheter portion 102. Controlled functionality from the actuation element 106 is provided in order to permit expansion and deployment of the implantable medical device at a desired location, such as a heart valve annulus or the aorta, and to provide for ease in the delivery and withdrawal of the delivery system through a patient's vasculature.

[0038] As illustrated in FIG. IB, which is an enlarged view of the catheter portion 102 and distal portion 104 with the introducer 107 removed, the catheter portion 102 of the delivery system 100 includes an outer shaft 108 that is also operatively connected with the actuation element 106 and that surrounds one or more inner members, e.g., a middle shaft 120 and an inner shaft 122 as discussed below in further detail with reference to FIGS. 2A-2C. The outer shaft 108 extends distally from the actuation element 106 and facilitates the advancement of the delivery system 100 along a guidewire and through a patient's vasculature. In some embodiments, the outer shaft 108 comprises one or more lubricous inner layers (such as high-density polyethylene (HDPE) or polytetrafluoroethylene (PTFE)), one or more braided stainless steel middle layers, and / or one or more flexible plastic outer layers, such as Pebax 7233, Pebax 6333, Nylon 12, and / or Vestamid ML24. In some embodiments, the outer shaft 108 optionally includes a hydrophilic coating to increase lubricity. In some examples, the outer shaft 108 includes a single spine extending longitudinally along all or a portion of its length, which can help with supporting axial loads at the distal end of the catheter portion 102 (such as prosthetic heart valve 150 contained in capsule 112) and more accurately transmit torque along the length of the catheter portion 102. In yet other embodiments, the outer shaft 108 may not include an axial spine. For example, in some cases the middle shaft 120 comprises a multilayer shaft (discussed below) that provides enough axial support for the delivery system during delivery and deployment that the outer shaft 108 need not include a spine.

[0039] In some implementations, the outer shaft 108 comprises a flexible but nonsteerable shaft. In other embodiments, the outer shaft 108 may include a steerable distal portion. In such embodiments, the outer shaft 108 can include one or more steering wires extending along its length, or may comprise a plurality of coaxial tubes having one or more steering tendons. Examples of the latter embodiments are provided below with reference to FIGS. 6-18B.

[0040] The outer shaft 108 is operatively coupled, at a proximal end, to the actuation element 106 so as to be movable by operation of the actuation element 106, and at a distal end is connected with a sheath or capsule 112. In some embodiments, the capsule 112 can be a separate component that is coupled to the outer shaft 108. In some embodiments, the capsuleMDT Ref. A0013458W001FortemRef. MDTSH.OOIWO 112 can be formed as an integrated extension of the outer shaft 108. The capsule 112 is configured to retain the implantable medical device, e.g., prosthetic heart valve or stent graft, in a radially collapsed configuration for delivery to the desired implantation location as will be described in more detail below. That is, telescopic movement of the outer shaft 108 by operation of the actuation element 106 causes the longitudinal translational movement of the capsule 112 proximally away from the distal portion 104, thereby exposing the implantable medical device, as illustrated in FIG. 1C. The actuation element 106 is configured to, among other things, control the advancement and the withdrawal of the capsule 112.

[0041] In some embodiments, as shown in FIG. IB, the catheter portion 102 of the delivery system 100 optionally includes a stability shaft 109. The stability shaft 109 is operatively coupled to a distal end of the actuation element 106 and extends over a portion of the length of the outer shaft 108. In some examples, the stability shaft 109 comprises a lubricous inner layer (such as high density polyethylene (HDPE) or polytetrafluoroethylene (PTFE)), a braided stainless steel middle layer, and a flexible plastic outer layer, such as comprised of Vestamid Care ML24, Green PMS 368, Pebax 7233, or Nylon 12. In some embodiments, the stability shaft 109 optionally includes a hydrophilic coating to increase lubricity. The stability shaft 109 extends to a desired length of the catheter portion 102 of the delivery system 100 from the actuation element 106. The stability shaft 109 facilitates the advancement of the delivery system along a guide wire and through a patient's vasculature by improving the pushability of the delivery system 100. An example of the stability shaft 109 in the anatomy is shown in FIG. 2. The stability shaft 109 may also add stiffness to the proximal end of the catheter portion 102 which translates into a more supportive structure for the catheter portion 102. This stiffness of the stability shaft 109 is configured to minimize movement of the catheter portion 102 within the anatomy during the deployment of the implantable medical device, thereby aiding the user in making a more accurate deployment. The increased stiffness and length of the stability shaft 109 resists the movement of the catheter portion 102 toward the inner curvature of the bend in the aorta. In some embodiments, the stability shaft 109 may be at least 50% the length of the outer 108 distal of the actuation element 106, such as at least 70% the length or about 80% the length.

[0042] FIG. 3 A illustrates an enlarged view of the distal portion 104 and catheter portion 102 in which the outer shaft 108, the capsule 112, and the stability shaft 109 are removed. FIG. 3B is a cross-sectional view taken along line B-B of FIG. 3 A. As illustrated, the delivery system 100 further includes a middle shaft 120 and an inner shaft 122. The middleMDT Ref. A0013458W001FortemRef. MDTSH.001WO shaft 120 may be slidingly disposed within the outer shaft 108 and operatively coupled to the actuation element 106. As used herein, “slidably” denotes back and forth (proximal and distal) movement in a longitudinal direction along or generally parallel to a central longitudinal axis LA of the delivery system 100. The inner shaft 122 is disposed within a lumen of the middle shaft 120. As with the outer shaft 108, the middle shaft 120 and the inner shaft 122 each distally extend from within the actuation element 106. Said another way, the proximal portions of each of the outer shaft 108, middle shaft 120, and inner shaft 122 are disposed at least partially within and coupled to the actuation element 106.

[0043] As best depicted in FIG. 3C, which is a cross-sectional view of the catheter portion 102 taken along line A-A of FIG. 1C, the outer shaft 108 defines a lumen 124 and is slidingly disposed over the middle shaft 120 in a coaxial arrangement. The middle shaft 120 defines a lumen 126 and is disposed over the inner shaft 122 in a coaxial arrangement. The inner shaft 122 defines a lumen 128 configured to receive a guidewire 129 therethrough such that the delivery system 100 may be slidingly disposed and tracked over a guidewire 129.

[0044] The middle shaft 120 may comprise an elongate tubular structure formed of one or more layers of polymers, metals (e.g., laser cut tube, HHS® tube, spring wound, solid shaft, etc.), or a combination of both (e.g., a polymer layer and a metal braided layer, a polymer layer and a laser-cut metal tube, etc.). In some implementations, the middle shaft 120 comprises a flexible but non-steerable shaft. In other embodiments, the middle shaft 120 may comprise a steerable distal portion. In such embodiments, the middle shaft 120 can include one or more steering wires extending along its length, or may comprise a plurality of coaxial tubes having one or more steering tendons. Examples of the latter embodiments are provided below with reference to FIGS. 6A-18B.

[0045] Referring still to FIGS. 3A-3C, the inner shaft 122 has a proximal end (not shown) which terminates within the actuation element 106 and a distal end 130 (FIG. 3B). In some examples, a tapered flexible nosecone or distal tip 132 may be coupled to the distal end 130 of the inner shaft 122. In some embodiments, the distal end 130 of the inner shaft 122 can be located within a channel 134 that extends from a proximal end 136 to a distal end 138 of the distal tip 132.

[0046] The middle shaft 120 has a proximal end (not shown) disposed within and operatively coupled to the actuation element 106 and a distal end 121 disposed inside of the capsule 112 when the capsule 112 is disposed over the implantable medical device. The distalMDT Ref. A0013458W001FortemRef. MDTSH.OOIWO end 121 of the middle shaft 120 may include or otherwise be coupled to a securing element 140 which is configured to be releasably coupled to an end of the implantable medical device, as discussed herein. In some embodiments, the distal end 121 of the middle shaft 120 and securing element 140 can include matching male and female threads to attach the securing element 140 to the distal end 121 of the middle shaft 120. The inner shaft 122 may be fixed to the middle shaft 120 at the securing element 140 such that the inner shaft 122 and the middle shaft 120 move axially as a single unit. The inner shaft 122 and middle shaft 120 are slidingly disposed within the outer shaft 108 and capsule 112.

[0047] The securing element 140 may comprise a tubular component having at least one recess 142 (e.g., one recess, two recesses, three recesses, four recesses, etc.) formed on an outer surface thereof that is configured to receive an attachment device (e.g., paddle, protrusion, etc.) extending from the implantable medical device. An example attachment device is described below with reference to FIGS. 5A and 5B. In some examples, the at least one recess 142 of the securing element 140 can be sized and shaped to closely correspond to the size and shape of the attachment device such that the attachment device is configured to fit within or mate with the recess 142 to releasably couple the implantable medical device to the middle shaft 120 and / or delivery system 100. Although only one recess 142 is visible in FIG.3 A, it will be appreciated that the securing element 140 may include two or more recesses for receiving a mating feature of the implantable medical device, such as for example first and second recesses at opposing circumferential locations on the securing element 140. Other securing element structures are possible.

[0048] According to some examples, the inner shaft 122 is configured to receive the implantable medical device, e.g., a self-expanding prosthetic heart valve 150 (not shown in FIGS. 3 A and 3B), on a distal portion thereof and the capsule 112 is configured to compressively retain the self-expanding prosthetic heart valve 150 on the distal portion of the inner shaft 122 during delivery. That is, the capsule 112 surrounds and constrains the self-expanding prosthetic heart valve 150 in a radially compressed or delivery configuration. As previously described, the distal end 121 of the middle shaft 120 includes the securing element 140 to which the self-expanding prosthetic heart valve is releasably coupled. During deployment of the self-expanding prosthetic heart valve in situ, the capsule 112 is proximally retracted with respect to the self-expanding prosthetic heart valve 150 via the actuation element 106, thereby incrementally exposing the self-expanding prosthetic heart valve 150 until the self-expanding prosthetic heart valve 150 is fully exposed and thereby released fromMDT Ref. A0013458W001FortemRef. MDTSH.OOIWO the securing element 140 and thus delivery system 100. That is, the middle shaft 120, the inner shaft 122, and the self-expanding prosthetic heart valve are held stationary while the outer shaft 108 and the capsule 112 are proximally retracted. When the capsule 112 is proximally retracted beyond the securing element 140, the attachment devices of the self-expanding prosthetic heart valve 150 are no longer held within the recesses 142 of the securing element 140 and the self-expanding prosthetic heart valve 150 is permitted to self-expand to its deployed configuration.|0049] As further illustrated in FIG. 3A, in some embodiments the middle shaft 120 can optionally have a more proximal length having a first diameter and a more distal length having a second diameter greater than the first diameter such that the middle shaft 120 includes a step 123 between the narrower proximal portion the wider distal portion. The delivery system 100 can further include a flush tube 160 positioned over the smaller diameter proximal portion of the middle shaft 120 with a distal end of the flush tube 160 abutting the step 123. The proximal end of the flush tube 160 can be configured to be coupled to a flush hub located in the actuation element 106. The middle shaft 120 can also be coupled to the flush hub located in the actuation element 106. For example, the flush tube 160 can have an inner diameter relative to the outer diameter of the middle shaft 120 so as to create an annular lumen between these respective surfaces so that flush fluid can be transported distally from the flush hub through the annular lumen.

[0050] When the flush hub of the actuation element 106 is coupled to the flush tube 160, flush fluid can enter the lumen between the flush tube 160 and the middle shaft 120 to flow distally from that point of the delivery system 100. The flush tube 160 can include openings 162 disposed near the step 123 of the middle shaft 120 and in fluid communication with the annular lumen between the flush tube 160 and the middle shaft 120. As such, the openings 162 enable fluid flow from the annular lumen into the lumen 124 (FIG. 3C) formed between the middle shaft 120 and the outer shaft 108, and thus to the inside of the capsule 112. This fluid path allows for flushing of the entire length of the delivery system 100 through the implantable medical device for removing air from the system.

[0051] With respect to each of the connections of the stability shaft 109, the outer shaft 108, the middle shaft 120, the inner shaft 122, and / or the flush tube 160 to other components of the system, an adhesive bonding connections can be utilized for fixing the shaft or tube ends in place. One skilled in the art, however, will realize that other bonding or securement techniques and procedures could instead be utilized, such as interference / press fit, seals / gaskets, threaded connections, melt or material welding, etc.MDT Ref. A0013458W001FortemRef. MDTSH.OOIWO

[0052] FIG. 4 illustrates an isolated side view of the actuation element 106. As illustrated, the actuation element 106 includes a base 402 and one or more actuators for controlling movement of the inner shaft 122, middle shaft 120, and / or outer shaft 108 and capsule 112. In some implementations, the actuation element 106 includes a first actuator 404 operatively coupled to the outer shaft 108 and capsule 112, a second actuator 405 operatively coupled to the inner shaft 122, and a third actuator 407 operatively coupled to the middle shaft 120. In some examples, the actuation element 106 includes only one or two of the first, second, and third actuators 404, 405, 407.

[0053] The first actuator 404 is operatively coupled to a proximal portion of the outer shaft 108 and is configured to be manipulated by a user to advance and retract the outer shaft 108 (and thereby advance and retract the capsule 112) relative to the rest of the delivery system 100. For example, during deployment of the self-expanding prosthetic heart valve in situ, the actuator 404 can be rotated relative to the base 402 in order to proximally retract the outer shaft 108 and the capsule 112 with respect to the middle shaft 120, inner shaft 122, and prosthetic heart valve 150. The actuator 404 can be incrementally rotated in a first circumferential direction in order to incrementally expose the prosthetic heart valve 150 until the prosthetic heart valve 150 is fully exposed and the attachment devices have released from the securing element 140 (FIGS. 2A and 2B). Likewise, the outer shaft 108 and the capsule 112 can be advanced distally by rotating the actuator 904 in a second circumferential direction opposite the first circumferential direction. In the embodiment shown, the first actuator 404 may move in an axial direction when rotated, for example, along a screw thread that is stationary relative to the base 402. In other embodiments, the first actuator 404 may remain stationary when rotated and an internal threaded screw or shaft may be translated in the axial direction by rotation of the first actuator 404. In these embodiments, the outer shaft 108 and capsule 112 may be operatively coupled to the internal threaded component and move therewith.

[0054] The second actuator 405 is operatively coupled to a proximal portion of the inner shaft 122 and is configured to be manipulated by a user to retract the inner shaft 122 in a proximal direction after the prosthetic heart valve has been deployed. In some embodiments, the inner shaft 122 is axially fixed relative to the middle shaft 120 such that the second actuator 405 may simultaneously retract both the inner and middle shafts 122, 120. Further details regarding the second actuator 405 may be found in U.S. Patent No. 9,486,604, filed May 11, 2012, which is hereby incorporated by reference in its entirety. The second actuator 405 is referred to as the “tip retractor” in the ‘604 Patent..MDT Ref. A0013458W001FortemRef. MDTSH.001WO

[0055] The third actuator 407 is operatively coupled to a proximal portion of the middle shaft 120 and is configured to be manipulated by a user to cause articulation of the distal portion of the middle shaft and / or cause all or a portion of the middle shaft 120 to transform from a flexible configuration into a rigid configuration, thereby locking the middle shaft 120 (or a portion thereof) in a desired shape. The third actuator 407 may comprise a single actuator or multiple actuators. In any case, the third actuator 407 may comprise one or more knobs, one or more levers, one or more sliders, one or more buttons, and / or other suitable actuators. Additional details regarding the third actuator 407 are described below with reference to FIGS.9B, 10 A, 10B, and 11.

[0056] In some embodiments, for example as shown in FIG. 4, the actuation element 106 may optionally include a proximal flush hub 406 and / or a distal flush hub 408. The proximal flush hub 406 can be configured to be in fluid communication with the flush tube 160.

[0057] In some implementations, the implantable medical devices useful with the present disclosure can be a prosthetic valve sold under the trade name Core Valve® available from Medtronic, Inc., Evolut™ Pro+ available from Medtronic, Inc., Evolut™ FX available from Medtronic, Inc., Evolut™ FX + available from Medtronic, Inc., and the like. A nonlimiting example of an implantable medical device useful with systems, devices and methods of the present disclosure is illustrated in FIGS. 5A and 5B. In other implementations, the implantable medical devices useful with the present disclosure can be an endovascular stent graft, such as the Medtronic Endurant™ or Valiant™ Captivia™ stent graft systems. In particular, FIG. 5A shows a side view of a prosthetic heart valve 500 in a normal or expanded (uncompressed) arrangement. FIG. 5B illustrates the prosthetic heart valve 500 in a compressed arrangement (e.g., when compressively retained within delivery system such as the distal portion 104 of the delivery system 100). The prosthetic heart valve 500 includes a stent or frame 502 and a valve structure 504. The stent 502 can assume any of the forms described above, and is generally constructed so as to be expandable from the compressed arrangement (FIG. 5B) to the uncompressed arrangement (FIG. 5A). In some embodiments, the stent 502 is self-expanding. The valve structure 504 is assembled to the stent 502 and provides two or more (typically three) leaflets 506. The valve structure 504 can be assembled to the stent 502 in various manners, such as by sewing the valve structure 504 to one or more of the wire segments or commissure posts defined by the stent 502.MDT Ref. A0013458W001FortemRef. MDTSH.OOIWO

[0058] The prosthetic heart valve 500 of FIGS. 5 A and 5B can be configured to replace or repair an aortic valve. Alternatively, other shapes are also envisioned, adapted to the specific anatomy of the valve to be repaired (e.g., stented prosthetic heart valves in accordance with the present disclosure can be shaped and / or sized for replacing a native mitral, pulmonic, or tricuspid valve). The prosthetic heart valve 500 may also be configured to replace a previously implanted surgical valve (TAV-in-SAV) or transcatheter valve (TAV-in-TAV). With the example of FIGS. 5A and 5B, the valve structure 504 extends less than the entire length of the stent 502, but in other embodiments can extend along an entirety, or a near entirety, of a length of the stent 504. A wide variety of other constructions are also acceptable and within the scope of the present disclosure. For example, the stent 502 can have a more cylindrical shape in the normal, expanded arrangement.

[0059] The stent 502 includes support structures that comprise a number of struts or wire portions 508 arranged relative to each other to provide a desired compressibility and strength to the valve structure 504. The stent 502 can also include one or more paddles 510 that removably couple the prosthetic heart valve 500 to a delivery system, e.g., the delivery system 100. While FIGS. 5A and 5B illustrate paddles 510, one skilled in the art will realize that the paddles 510 can be replaced with other components such as eyelets, loops, slots, or any other suitable coupling member. The paddles 510 can include one or more radiopaque markers or cut-outs that aid in the positioning and orientation of the prosthetic heart valve 500. The struts or wire portions 508 form a lumen having an inflow end 512 and an outflow end 514. Radiopaque markers may be included, such as adjacent the inflow end 512, to aid in depth alignment and / or rotational orientation. The struts or wire portions 508 can be arranged such that the struts or wire portions 508 are capable of transitioning from the compressed arrangement to the uncompressed arrangement. These wires are arranged in such a way that the stent 502 allows for folding or compressing or crimping to the compressed arrangement in which the internal diameter is smaller than the internal diameter when in the uncompressed arrangement. In the compressed arrangement, the stent 502 with attached valve structure 504 can be mounted onto a delivery system, such as the distal portion 104 the delivery system 100. The stent 502 are configured so that they can be changed to an uncompressed arrangement when desired, such as by the relative movement of one or more sheaths relative to a length of the stent 502.

[0060] In some examples, the wires of the support structure of the stent 502 in embodiments of the present disclosure can be formed from a shape memory material such as aMDT Ref. A0013458W001FortemRef. MDTSH.001WO nickel titanium alloy (e.g., Nitinol). With this material, the support structure is self-expandable from the compressed arrangement to the normal, expanded arrangement, such as by the application of heat, energy, and the like, or by the removal of external forces (e.g., compressive forces). This stent 502 can also be compressed and re-expanded multiple times without significantly damaging the structure of the stent frame. In addition, the stent 502 of such an embodiment may be laser-cut from a single piece of material or may be assembled from a number of different components or manufactured from a various other methods known in the art.

[0061] According to some examples, the stent 502 comprises one or more tubular support structures having an internal area in which the leaflets 506 can be secured. The leaflets 506 can be formed from a variety of materials, such as autologous tissue, xenograph material, or synthetics as are known in the art. In some embodiments, the leaflets 506 may be formed from porcine, bovine, or equine pericardium. In some embodiments, the leaflets 506 can be provided independent of one another and subsequently assembled to the support structure of the stent 502. In some embodiments, the stent 502 and the leaflets 506 can be fabricated at the same time, such as may be accomplished using high-strength nano-manufactured NiTi films produced at Advanced Bioprosthetic Surfaces (ABPS), for example. The stent 502 can be configured to accommodate at least two (typically three) of the leaflets 506 but can incorporate more or fewer than three of the leaflets 506.

[0062] Further examples and descriptions of prosthetic heart valves and delivery systems may be found in U.S. Application No. 17 / 543,230, filed December 6, 2021, and U.S. Patent No. 12,144,728, filed December 2, 2021, each of which is hereby incorporated by reference herein in its entirety for all purposes. Components of delivery systems described therein may be combined with those described in the present disclosure and prosthetic heart valves described therein may be combined with the delivery systems described in the present disclosure.II. Multilayer Shafts

[0063] According to some examples of the present technology, the middle shaft 120 may comprise a flexible elongate shaft formed of a plurality of coaxially arranged elongate tubular members with a steerable and / or selectively rigidizable distal portion. The multilayer shafts discussed below are also referred to herein as “ML shafts.” FIG. 6A, for example, shows an elongate shaft 600 (or “ML shaft 600”) for use with the delivery systems of the presentMDT Ref. A0013458W001FortemRef. MDTSH.OOIWO technology, the ML shaft 600 comprising an outer elongate tubular member 630 (or “outer member 630”), an intermediate elongate tubular member 620 (or “intermediate member 620”) disposed within a lumen of the outer member 630, and an inner elongate tubular member 610 (or “inner member 610”) disposed within a lumen of the intermediate member 620. In some implementations, the ML shaft 600 may comprise only two elongate tubular members. In yet other examples, the ML shaft 600 may comprise more than three elongate tubular members such that the ML shaft 600 (e.g., four elongate tubular members, five elongate tubular members, six elongate tubular members, etc.).

[0064] As shown in FIG. 6A, the ML shaft 600 includes a proximal portion 600a configured to be coupled to an actuation element (such as actuation element 106), a distal portion 600b, and an intermediate portion 600c extending therebetween. The distal portion 600b and / or the intermediate portion 600c is configured to be positioned in a body lumen, with the distal portion 600b including at least one steerable region 602 configured to be selectively deflected in response to a steering input at the proximal portion 600a. As discussed herein, in some embodiments the actuation element 106 may include one or more actuators that are operatively coupled to the ML shaft 600 and configured to move one or more regions of the ML shaft 600. The steerable region 602 may be configured to deflect in a single plane (e.g., bi-directional) or multiple planes (e.g., omni-dimensional). While only a single steerable region 602 is shown in FIG. 6A, in some examples the ML shaft 600 may have two or more steerable regions 602, each independently controllable at the proximal portion 600a. The intermediate portion 600c of the ML shaft 600 may be passively bendable and / or flexible, for example to accommodate one or more turns in the body lumen.

[0065] FIG. 6B shows a delivery system 100 incorporating the ML shaft 600 as the middle shaft 120, positioned in the aorta in a curved configuration with the catheter portion 102 around the aortic arch and the distal portion 104 in the ascending aorta, with at least a portion of the capsule 112 aligned with the valve annulus (indicated schematically with the dashed line). The ML shaft 600 / middle shaft 120 is not visible under the outer shaft 108 but the location of the various regions are still indicated in the drawing for ease of explanation. The steerable region 602 of the ML shaft 600 is thus shown in a curved configuration, which may be a result of active deflection by the user at the proximal portion 600a or passive adaptation to the aortic curvature. In any case, once in this curved position, the steerable region 602 may be temporarily transformed into a rigid configuration such that the shape of theMDT Ref. A0013458W001FortemRef. MDTSH.OOIWO steerable region 602 becomes fixed, the mechanism of which is discussed below with reference to FIGS. 9B-11.

[0066] As demonstrated by FIG. 6B, the steerable region 602 is configured to assume a maximum predetermined curvature, whether in response to a steering input or passively in response to the curvature of the local anatomy. The degree of curvature can be determined, for example, by a cut pattern of the flexible regions 618, 628, 638 (discussed below) of the inner, intermediate, and outer members 610, 620, and 630. The steerable region 602 can be configured to assume a single radius of curvature, or in some embodiments to assume two or more distinct radii of curvature, for example to accommodate different turns in the vasculature. As shown in FIGS. 6 A and 6B, in some embodiments the steerable region 602 can have a first portion 702 and configured to be deflected to a first radius of curvature and a second portion 704 configured to be deflected to a second radius of curvature. To achieve the different bending radii, the flexible regions 618, 628, 638 of one, some, or all of the underlying inner, middle, and / or outer members 610, 620, 630 can have two distinct cut patterns. Depending on the desired use, the first and second portions 702, 704 can have the same or different lengths (as measured along the longitudinal axis of the ML shaft 600). For instance, when used for delivering prosthetic valves to a native aortic annulus, the first portion 702 can be shorter than the second portion 704, as the first portion 702 is configured to be positioned in the shorter ascending aorta and the second portion 704 is configured to be positioned in the longer aortic arch. Likewise, the first portion 702 can be configured to assume a radius of curvature that is less than a radius of curvature of the second portion 702, again to accommodate the sharper bend in the ascending aorta.

[0067] In some embodiments, the first portion 702 of the steerable region 602 has a length of about 30 mm to about 50 mm, or no more than 40 mm, or no more than 41 mm, and a radius of curvature of about 5 mm to about 40 mm, 10 mm to about 20 mm, 10 mm to about 30 mm, at least 10 mm, no more than 40 mm, or no more than 30 mm, while the second portion 704 of the steerable region 602 has a length of about 60 mm to about 80 mm, or no more than 80 mm, or no more than 70 mm, and a radius of curvature of about 10 mm to about 40, or about 20 mm to about 30 mm. In these and other embodiments, the steerable region 602 can have a length of about 100 mm to about 130 mm, or about 100 mm to about 120 mm, or about 110 mm, or about 111 mm, and can be configured to bend greater than 180 degrees such that the distal tip 132 points back towards the more proximal portion of the catheter portion 102, as shown in FIG. 6B. The radii of curvature listed herein can represent, in some embodiments,MDT Ref. A0013458W001FortemRef. MDTSH.OOIWO the maximum radius of curvature to which the steerable region 602 can bend. It will be appreciated that other lengths and radii of curvature are possible.

[0068] In some implementations, the ML shaft 600 can have an outer diameter of about 3.0 mm to about 4.5 mm, about 3.4 mm to about 4.0 mm, about 3.7 mm, or no less than 3.7 mm. Additionally or alternatively, the ML shaft 600 can have an inner diameter of about 2.0 mm to about 3.5 mm, about 2.3 mm to about 2.9 mm, about 2.6 mm, or no less than 2.6 mm. The ML shaft 600 can have a total length of from about 1400 to 1500 mm, or about 1450 mm, or no less than 1450 mm.

[0069] As shown in the exploded view of the ML shaft 600 in FIG. 7, each of the inner, intermediate, and outer members 610, 620, and 630 can have distal portions 610b, 620b, 630b that include one or more flexible regions 618, 628, 638 that are aligned with one another when the inner, intermediate, and outer members 610, 620, and 630 are assembled into the ML shaft 600. Each of the inner, intermediate, and outer members 610, 620, 630 also include a respective intermediate portion 610c, 620c, 630c that may be passively bendable and / or flexible (e.g., to accommodate one or more turns in the body lumen) but not steerable. The flexible regions 618, 628, 638 may include a plurality of cuts and / or slits in the respective tubular sidewall, such as circumferentially extending cuts and / or helically extending cuts, etc., configured to improve the flexibility and / or bendability of the respective elongate member along that region. Likewise, each of the intermediate portions 610c, 620c, 630c may include a plurality of cuts and / or slits (not shown in FIG. 7), such as circumferentially extending cuts and / or helically extending cuts, etc., configured to improve the flexibility and / or bendability of the respective elongate member along that region.

[0070] In some embodiments, one, some, or all of the inner, intermediate, and outer members 610, 620, and 630 include rigid bands at their respective distal end portions 614, 624, 634 at which the inner, intermediate, and / or outer members 610, 620, 630 are fixed to one another. As such, the ML shaft 600 can include a rigid portion 601 at the distal end. The rigid bands may comprise a rigid portion of the sidewall forming the respective elongate tubular member. The rigid bands (and thus the inner, intermediate, and outer members 610, 620, and 630) can be fixed to one another via welding or other techniques. In some embodiments, the rigid bands are welded to one another at one or more discrete weld spots 623. The inner, intermediate, and outer members 610, 620, 630 can also be fixed to one another at one or more other locations along the length of the ML shaft 600, such as along their respective intermediate portions 610c, 620c, 630c and / or proximal portions 610a, 620a, 630a. In some embodiments,MDT Ref. A0013458W001FortemRef. MDTSH.OOIWO one, some, or all of the inner, intermediate, and outer members 610, 620, and 630 include rigid bands at their respective proximal end portions 612, 622, 632 and are fixed to one another at the rigid bands.

[0071] As previously mentioned, FIG. 6A shows an example in which the distal portions 610b, 620b, 630b of the inner, intermediate, and outer members 610, 620, and 630, respectively, have only a single flexible region, corresponding to a single steerable region 602 on the ML shaft 600. In those embodiments in which the ML shaft 600 has multiple distinct steerable regions 602, each of the distal portions 610b, 620b, 630b will have multiple flexible regions. In such embodiments, the flexible regions along a given member may be separated from an axially adjacent flexible region by a rigid band, as discussed in greater detail below with reference to FIG. 12.

[0072] As shown in FIG. 7, the intermediate member 620 may further include one or more tendons 626, each associated with and / or extending through a respective flexible region 628 such that axial movement of a tendon 626 causes articulation of its corresponding flexible region 628, as well as articulation of the flexible regions 618 and 638 of the inner and outer members 610, 630. As such, actuation of the tendons 626 causes articulation of the steerable region 602. In some embodiments, a distal end of a tendon 626 may be coupled to (e.g., integrally formed with, or attached such as via at least one weld) a rigid band just distal of the corresponding flexible region 628. For example, in FIG. 7, the distal end of tendon 626 is integral with the rigid band comprising the distal end portion 624 of the intermediate member 620. In any case, axial movement of the tendon 626 can be controlled via an actuation element (such as actuation element 106) operatively coupled (directly or indirectly) to a proximal end of the tendon 626.

[0073] A tendon 626 may be formed as a longitudinal member or strip extending longitudinally along at least a portion of a wall of the intermediate member 620, for all or a portion of the length of the intermediate member 620. A tendon 626 may be cut from the sidewall of the intermediate member 620 and thus integral with the sidewall of the intermediate member 620. A tendon 626 may be configured to move generally in a longitudinal direction within a respective slot 629 defined by (and cut from) the wall of the intermediate member 620. On either side of a tendon 626 or slot 629 can be a tendon-adjacent portion 627 of the sidewall that is not configured to move longitudinally and / or be actuated and is separated from the tendon 626 by a slit. The slit may, for example, be formed by removal of material such as laserMDT Ref. A0013458W001FortemRef. MDTSH.OOIWO cutting, where the width of the slit corresponds to the width of the laser beam. The slot 629 may also be formed via laser cutting or another material removal process.

[0074] In the example shown in FIG. 7, the tendon 626 and slot 629 are generally linear and extend in a longitudinal direction. However, in some embodiments the tendon 626 and slot 629 may be any suitable shape generally extending in a longitudinal direction, such as a helical shape that wraps in a spiral manner around the wall of the intermediate member 620. For example, FIG. 8 illustrates an example intermediate member 820 (an example of intermediate member 620) that includes multiple helical tendons 826 that have been obtained after making helical slits 825 (only a few labeled) in the wall of the intermediate member 820. The tendon-adjacent portions 827 of the sidewall may also extend helically. The spiraling path taken by the tendons 826 beneficially compensates path length changes in the tendons 826 caused by any bending of the intermediate portion of the intermediate member 820, for instance when the shaft is inserted in a tortuous path.

[0075] Referring again to FIG. 7, in some embodiments, a tendon 626 may be actuated via an actuating input applied to a feature of the outer member 630. For example, in some embodiments the outer member 630 may include at least one slider 636 configured to move within a respective slot 639 defined by the outer member 630. Each slider 636 may be coupled to an underlying tendon 626 (e.g., via epoxy, spot welding, etc.) such that movement of the slider 636 results in movement of its associated tendon 626. The outer member 630 may include multiple sliders 636 and slots 639, where each slider 636 is coupled to a respective tendon 626, such as selective actuation of the sliders 636 results in selective movement of tendons 626 and thus selective articulation of the steerable region 602 of the ML shaft 600.

[0076] Although only one tendon 626 is visible in the example shown in FIG. 7, the intermediate member 620 may include any suitable number of tendons 626. For example, in some embodiments a second tendon 626 may be located on a circumferentially opposite side of the intermediate member 620. For example, two tendons 626 may be circumferentially offset about 180 degrees from one another and operate in an antagonistic manner to articulate a flexible region 628 to which the two tendons 626 are coupled. For instance, a first tendon 626 may be pulled proximally in a longitudinal direction (and / or a second tendon 626 arranged circumferentially opposite to the first tendon 626 may be pushed distally in a longitudinal direction) to cause bending of the flexible region 628 in a first direction. The second tendon 626 may be pulled proximally in a longitudinal direction (and / or the first tendon 626 may be pushed distally in a longitudinal direction) to cause bending of the flexible region 628 in a secondMDT Ref. A0013458W001FortemRef. MDTSH.001WO direction (e.g., opposite the first direction). Two circumferentially offset (e.g., 180 degrees) tendons 626 per flexible region 618 enable steering of the flexible region in a single plane (or bi-directional steering), while four tendons 626 circumferentially offset from one another (e.g., by about 90 degrees) enable steering of the flexible region in multiple planes (or omnidirectional steering). Other numbers of tendons and spacings are possible.

[0077] In those embodiments in which the intermediate member 620 has multiple discrete flexible regions 628 (and thus the ML shaft 600 has multiple steerable regions 602), each flexible region 628 is coupled to a different set of one or more tendons 626. For example, a first group of tendons 626 may be coupled to a first, more distal flexible region 628 and a second group of tendons 626 may be coupled to a second, more proximal flexible region 628. The number of tendons 626 in each of the first and second groups of tendons 626 depends on the desired steering and / or bending properties of the steerable region associated with each flexible region. For example, as previously explained, a steerable region requiring omnidirectional steering may include four or more tendons 626, while a steerable region requiring only bi-directional steering may include two tendons 626. The number of tendons 626 in the first and second groups of tendons 626 may be the same or different. Because a distal end of the first, more distal flexible region 628 is distal of the distal end of the second, more proximal flexible region 628, the tendons 626 in the first group of tendons 626 will be longer (and extend distally beyond) the tendons 626 in the second group of tendons 626. An example of an ML shaft 600 having two steerable regions 602 is described below with reference to FIGS. 12-13C.

[0078] The inner member 610, the intermediate member 620, and the outer member 630 of the ML shaft 600 may be assembled to form a combined unit that defines the ML shaft 600. For example, the inner member 610 may be inserted into the intermediate member 620, and the combined inner member 610 and intermediate member 620 subassembly may be inserted into the outer member 630, although any order of insertion may be possible. Various features of the elongate members of the ML shaft 600 (e.g., articulable regions, tendons, sliders, slots, etc.) may be formed through removal of material from the wall of each respective tube forming the members of the ML shaft 600. For example, starting from a cylindrical tube with desired inner and outer diameters (and desired wall thickness), various features of an elongate member may be formed by removing parts of the wall of the cylindrical tube, such as by laser cutting or water cutting. However, in some embodiments the elongate members may be formed through injection molding, plating techniques, 3D printing or otherMDT Ref. A0013458W001FortemRef. MDTSH.OOIWO material deposition process, photochemical etching, deep pressing, conventional chipping techniques such as drilling or milling, and / or any suitable technique. In some embodiments, removal of material may be performed through laser cutting, which may allow for a very accurate and clean removal of material under reasonable economic conditions.

[0079] The inner member 610, intermediate member 620, and / or outer member 630 may be formed from any suitable rigid material such as stainless steel, cobalt-chromium, shape memory alloy such as Nitinol®, plastic, polymer, composites and / or other materials. Additionally or alternatively, the elongate member(s) (e.g., inner member 610, intermediate member 620, and / or outer member 630) can be made by a 3D printing process or other known material deposition processes. In some embodiments, a lubricant is disposed between radially adjacent elongate tubes.

[0080] FIG. 9A shows an enlarged view of a distal portion of an example delivery system, similar to delivery system 100, that utilizes the ML shaft 600 as the previously described middle shaft 120. As shown, a distal end of the ML shaft 600 can be coupled to a securing element (such as securing element 140 or other securing elements, as described herein) for detachably coupling the delivery system to a prosthetic heart valve (not shown). The inner shaft 122 is disposed within a lumen of the ML shaft 600, and the ML shaft 600 is disposed within a lumen of the outer shaft 108 (not visible) and capsule 112. The inner shaft 122 may also be coupled to the securing element 140 such that the securing element 140, inner shaft 122, and ML shaft 600 can be moved axially as a unit.

[0081] FIG. 9B shows an enlarged view of the proximal portion 620a of the intermediate member 620, the proximal portion 630a of the outer member 630, and an example control interface 650 for operatively coupling the ML shaft 600 with an actuation element, such as a handle or robotic system, for controlling articulation of the steerable region 602. The control interface 650 includes first, second, and third tubular structures 650A, 650B, 650C. The second tubular structure 650B is configured to be positioned within a lumen of the third tubular structure 650C, the first tubular structure 650A is configured to be positioned within a lumen of the second tubular structure 650B, and all or a portion of the proximal portion 630a of the outer member 630 is configured to be positioned in a lumen of the first tubular structure 650A. The dashed lines in FIG. 9B depict example weld locations between the tubular structures and elongate members and are not intended to be limiting. More or fewer locations are possible.MDT Ref. A0013458W001FortemRef. MDTSH.001WO

[0082] The first tubular structure 650A may comprise a first bushing 651, a first grounding band 654a, a second bushing 652, and a second grounding band 654b. Each of the first and second bushings 651, 652 may comprise a tube configured to be disposed over the proximal portion 630a of the outer member 630 and rotatable around an outer surface of the outer member 630 (as indicated by the arrows). The first bushing 651 can have first and second helical slots 659a, 660a, each wrapping around the longitudinal axis in opposite directions, and first sliders 656a, 658a (only slider 656a is visible in FIG. 9B), each slidably disposed in a corresponding one of the helical slots 659a, 660a. The first and second slots 659a, 660a and the first sliders 656a, 658a may be cut from the tubular sidewall of the first bushing 651. The second bushing 652 can have first and second helical slots 659b, 660b, each wrapping around the longitudinal axis in opposite directions, and second sliders 656b, 658b (only slider 656b is visible in FIG. 9B), each slidably disposed in a corresponding one of the helical slots 659b, 660b. The first and second slots 659b, 660b and the second sliders 656b, 658b may be cut from the tubular sidewall of the second bushing 652.

[0083] As previously mentioned, the ML shaft 600 is configured for articulation of the steerable region 602 in multiple planes, and thus the intermediate member 620 has four tendons — one antagonistic pair 626a for bending in a first plane, and one antagonistic pair 626b for bending in a second plane). In FIG. 9B, only one tendon of each pair is visible. The outer member 630 has four slots and corresponding sliders — a first slot 639a and first slider 636a, each pairing with one of the first tendons 626a, and a second slot 639b and second slider 636b, each pairing with one of the second tendons 626b. Only one of the two first slots / sliders and only one of the two second slots / sliders are visible in FIG. 9B. As indicated by the dashed lines, when the ML shaft 600 is assembled with the bushings 651, 652, the first tendons 626a are fixed (e.g., spot welded) to the first outer member sliders 636a, and the second tendons 626b are fixed (e.g., spot welded) to the second outer member sliders 636b. The first outer member sliders 636a are fixed (e.g., spot welded) to the first bushing sliders 656a, and the second outer member sliders 636b are fixed (e.g., spot welded) to the second bushing sliders 656b.

[0084] As previously mentioned, the first and second bushings 651, 652 are free to rotate around the longitudinal axis of the ML shaft 600. Because of the helical shape of the first and second slots 659a, 660a, rotation of the first bushing 651 forces the first bushing sliders 656a, 658a to move axially, thereby causing the first outer member sliders 636a and first tendons 626a to move axially, and thereby causing articulation of the steerable region 602 in a first plane. Because the helical slots 659a, 660a are wound in opposite directions, the firstMDT Ref. A0013458W001FortemRef. MDTSH.OOIWO bushing slider 656a in the first helical slot 659a will move in a first axial direction (proximal or distal) and the first bushing slider 656a in the second helical slot 660a will move in a second axial direction opposite of the first axial direction (proximal or distal). Likewise, because of the helical shape of the first and second slots 659b, 660b, rotation of the second bushing 652 forces the second bushing sliders 656a, 658a to move axially, thereby causing the second outer member sliders 636b and second tendons 626b to move axially, and thereby causing articulation of the steerable region 602 in a second plane. Because the helical slots 659b, 660b are wound in opposite directions, the second bushing slider 656b in the second helical slot 659b will move in a first axial direction (proximal or distal) and the second bushing slider 656b in the second helical slot 660b will move in a second axial direction opposite of the first axial direction (proximal or distal).

[0085] In some implementations, the control interface 650 can include a mechanism for fixing the axial position of one or both of the first and second tendons 626a, 626b, thereby locking the steerable region 602 in a desired shape and preventing additional articulation. Such a feature may be beneficial, for example, for holding the delivery system in a desired angle or position relative to a targeted valve region while deploying the prosthetic heart valve (or other implantable device) at the valve region (or target region). In some examples, the second and third tubular structures 650B, 650C are configured to engage with one another and the first tubular structure 650A to provide such a locking mechanism. The first, second, and third tubular structures 650A, 650B, 650C are configured to be selectively transformed between a locked state in which the steerable region 602 of the ML shaft 600 is substantially rigid and an unlocked state in which the steerable region 602 is flexible and configured to passively bend and flex to accommodate the curvature of the vasculature and / or other body lumen in which it is positioned. In this unlocked state, the control interface 650 allows for back-driving of the tendons 626 in response to passive bending of the steerable region 602, as the axial positions of the tendons change to accommodate their position on the curve. For example, the proximal end of a first tendon 626a on the inside of a curve will be proximal of the proximal end of its antagonistic first tendon 626a on the outside of the curve, which must shift distally to accommodate the extra length of the curve (assuming the antagonistic tendons have the same length).

[0086] The second tubular structure 650B can include a first tube portion 671, a second tube portion 672, a first grounding band 674a, and a second grounding band 674b. When the control interface 650 is assembled, the first tube portion 671 is at least partially axially alignedMDT Ref. A0013458W001FortemRef. MDTSH.001WO with the first bushing 651 and the second tube portion 672 is at least partially axially aligned with the second bushing 652. The first tube portion 671 can be fixed to the first bushing 651 at one or more locations (e.g., via spot welding) and the second tube portion 672 can be fixed to the second bushing 652 at one or more locations (e.g., via spot welding). Likewise, the first grounding band 674a can be fixed to the first grounding band 654a at one or more locations (e.g., via spot welding) and the second grounding band 674b can be fixed to the second grounding band 654b at one or more locations (e.g., via spot welding). The first and second grounding bands 654a, 654b are fixed at one of more locations to a stationary portion of another elongate tubular member, such as the outer member 630. As such, rotation of the first tube portion 671 causes rotation of the first bushing 651, and rotation of the second tube portion 672 causes rotation of the second bushing 652. The first grounding band 674a can be disposed at a proximal or distal end of the first bushing 651 (shown in FIG. 9B at the proximal end) and is fixed rotationally. The second grounding band 674b can be disposed at a proximal or distal end of the second bushing 652 (shown in FIG. 9B at the proximal end) and is fixed rotationally.

[0087] The third tubular structure 650C can include a first frame 681, a second frame 682, a first locking band 676a, and a second locking band 676b. The first frame 681 includes linear first slots 689a and first islands 686a slidably disposed within the first slots 689a. Both the first slots 689a and first islands 686a can be cut from the tubular sidewall forming the first frame 681. The first frame 681 may optionally include one or more recesses 683a (two shown in FIG. 9B) configured to engage an actuation element, as described herein. The first islands 686a may be fixed to the first tube portion 671 at one or more locations (e.g., via spot welding), while the first frame 681 remains slidable (indicated by the arrow A3) over the first tube portion 671, at least to the extent allowed by the first slots 689a and first islands 686a. As such, rotation of the first frame 681 causes rotation of the first tube portion 671 and thus rotation of the first bushing 651, while axial movement of the first frame 681 is isolated from, and does not cause translation of, the first tube portion 671 and first bushing 651.

[0088] The first locking band 676a can be disposed at a proximal or distal end of the first frame 681 (shown in FIG. 9B at the proximal end) and is fixed rotationally. In some embodiments, the first locking band 676a is fixed to the first grounding band 674a at one or more locations (e.g., via spot welding). As demonstrated by FIGS. 9C and 9D, the first frame 681 is configured to translate in and out of engagement with the first locking band 676a to enable / disable rotation of the first frame 681. In some embodiments, a proximal end of the first frame 681 can have a first engagement surface 665a and a distal end of the first locking bandMDT Ref. A0013458W001FortemRef. MDTSH.OOIWO 676a can have a second engagement surface 667a configured to mate with the first engagement surface 665a. The first and second engagement surfaces 665a, 667a can have complementary shapes and / or topographies, such as castellations, serrations, teeth, one or more protrusions, or other features configured to prevent relative rotation between the first and second engagement surfaces 665a, 667a (and thus the first frame 681 and first locking band 676a). When the first frame 681 is engaged with the first locking band 676a, the first frame 681, first tube portion 671, and first bushing 651 are all prevented from rotating, thereby preventing axial movement of the first sliders 636a of the outer member 630 and first tendons 626a of the intermediate member 620, thereby preventing articulation of the steerable region 602 in a first plane. Accordingly, the first frame 681 is configured to be translated in a first axial direction (proximally or distally, depending on the position of the first locking band 676a) into engagement with the first locking band 676a, thereby preventing articulation of the steerable region 602 in a first plane. When passive flexing of the steerable region 602 in the first plane is once again desired, the first frame 681 can be translated in a second axial direction, opposite the first direction such that the first and second engagement surfaces 665a, 667a are no longer in contact with one another, thereby enabling axial movement of the first tendons 626a and articulation of the steerable region 602 in the first plane.

[0089] In some embodiments, the first locking band 676a is configured to move axially into and out of contact with the first frame 681 to prevent / enable rotation of the first frame 681, while the first frame 681 remains axially stationary.

[0090] The description of the components, connections, and operation of the first bushing 651, first tube portion 671, and first frame 681 applies to the second bushing 652, second tube portion 672, and second frame 682. Axial and rotational movement of the first bushing 651, first tube portion 671, and first frame 681 may be independent of axial and rotational movement of the second bushing 652, second tube portion 672, and second frame 682. The first and second bushings 651, 652 may be selectively locked or unlocked at the same or different times. In some embodiments, axial movement of the first and second frames 681, 682 and / or first and second locking bands 676a, 676b may be tied to a single actuator (e.g., a lever, knob, button, slider, etc.) disposed on the actuation element such that the axial positions of the first and second tendons 626a, 626b may be locked with a single movement, thereby rigidizing the steerable region 602 in all directions at once.

[0091] FIG. 10 shows a portion of an actuation element 1006 operatively coupled to the proximal portion of the ML shaft 600 and control interface 650. The actuation element 1006MDT Ref. A0013458W001FortemRef. MDTSH.001WO can be generally similar to, and include all or some of the same components as, actuation element 106. The actuation element 1006 includes an actuator 1007 (similar to third actuator 407) configured to be operatively coupled to the ML shaft 600, for example via the control interface 650. The actuator 1007 can comprise first and second actuators, each configured to engage a pair of tendons 626a, 626b. In the example shown in FIG. 10, the actuators comprise a first knob 1081 coupled to the first frame 681 and a second knob 1082 coupled to the second frame 682. As shown in the cross-sectional view of the first knob 1081 in FIG. 11, the first and second knobs 1081, 1082 can have one or more protrusions 1084 along an interior surface that is configured to be received by the recesses 683a, 683b of the first and second frames 681, 682. As a result, the first and second knobs 1081, 1082 are fixed rotationally relative to the first and second frames 681, 682 such that rotation of the first and second knobs 1081, 1082 causes rotation of the first and second frames 681, 682 (and vice versa, during backdriving). The frames 681, 682 can have end portions on either side of the recesses 683a, 683b that prevent axial movement between the first and second knobs 1081, 1082 and the first and second frames 681, 682. As such, translation of the first and second knobs 1081, 1082 causes translation of the first and second frames 681, 682.

[0092] Rotation of the first knob 1081 causes rotation of the first bushing 651 (and thus articulation of the steerable region 602 in a first plane) and axial movement of the first knob 1081 causes translation of the first bushing 651 (thereby locking and unlocking the axial positions of the first tendons 626a to prevent / enable articulation). Likewise, rotation of the second knob 1082 causes rotation of the second bushing 652 (and thus articulation of the steerable region 602 in a second plane), and axial movement of the second knob 1082 causes translation of the second bushing 652 (thereby locking and unlocking the axial positions of the second tendons 626b to prevent / enable articulation).

[0093] As previously stated, the ML shaft 600 may be configured such that when the first and second knobs 1081, 1082 (or other tendon actuator) are in the unlocked position, movement at the distal region of the ML shaft 600 may back-drive the actuators. Stated another way, if the actuators are unlocked, movement at the distal region of the ML shaft 600 may cause the actuators to move (e.g., rotate, for a rotational actuator such as knobs 1081, 1082, slide, for a sliding actuator, etc.). This may apply if both actuators are unlocked or it may apply to one actuator if one is unlocked and the other is locked (e.g., only the unlocked actuator will back-drive). This configuration may be beneficial for several reasons. First, while tracking the delivery system to the deployment location, such as the aortic valve, mitral valve, tricuspidMDT Ref. A0013458W001FortemRef. MDTSH.OOIWO valve, or pulmonary valve, the actuators may be placed in the unlocked state to allow the ML shaft 600 and the delivery system to be flexible and conform to the anatomy of the aorta. If one or both of the actuators were in the locked position, this may prevent or reduce the ability of the delivery system to bend or flex in the locked plane.

[0094] It will be appreciated that while the steerable region 602 of the ML shaft 600 is capable of being actively articulated while traversing the anatomy, in some cases the user may choose to deliver and / or withdraw the delivery system with the distal portion 600b of the ML shaft 600 (e.g., middle shaft) in a flexible state, allowing the steerable region 602 to passively bend and straighten as needed to adapt to the local anatomy. In some cases, the user may choose to perform the entire procedure without utilizing the steering capabilities of the ML shaft 600 and only utilize the control interface to lock the shape of the distal portion 600b (i.e., hold the distal portion 600b in a rigid state) during deployment of the prosthetic heart valve.

[0095] According to some embodiments of the present technology, the ML shaft can include multiple, independently controllable steerable regions. For example, FIGS. 12-13C show an elongate shaft 1200 (or “ML shaft 1200”) having first and second steerable regions 1202a, 1202b (labeled in FIG. 13A). FIG. 12 is an exploded view of the ML shaft 1200, and FIG. 13 A shows the ML shaft 1200 in a curved configuration. The ML shaft 1200 can comprise coaxially arranged outer, intermediate, and inner elongate tubular members 1210, 1220, 1230, as described above with reference to FIGS. 6-8. The ML shaft 1200 can be generally similar to the ML shaft 600 except where noted herein. Each of the distal portions 1210b, 1220b, 1230b of the inner, intermediate, and outer members 1210, 1220, and 1230 include first and second flexible regions 1218a-b, 1228a-b, 1238a-b, respectively. When the inner, intermediate, and outer members 1210, 1220, and 1230 are assembled into the ML shaft 1200, the first flexible regions 1218a, 1228a, 1238a are axially aligned with one another and form the first steerable region 1202a, and the second flexible regions 1218b, 1228b, 1238b are axially aligned with one another and form the second steerable region 1202b.

[0096] Each pair of first and second flexible regions 1218a-b, 1228a-b, 1238a-b on a given elongate member may be separated by a rigid portion and / or rigid band 1213, 1223, 1233 formed by the sidewall of the respective elongate tubular member. The inner, intermediate, and outer members 1210, 1220, 1230 may be fixed to one another at their respective rigid portions 1213, 1223, 1233, thereby forming a rigid portion 1203 (see FIG. 13A) between the first and second steerable regions 1202a, 1202b. The ML shaft 1200 further includes a rigid portionMDT Ref. A0013458W001FortemRef. MDTSH.OOIWO 1201 at the distal end at which the inner, intermediate, and outer members 1210, 1220, 1230 are fixed to one another, as described above with reference to ML shaft 600.

[0097] The ML shaft 1200 can comprise more or fewer than three elongate tubular members, such as two elongate tubular members, four elongate tubular members, five elongate tubular members, etc.

[0098] Each of the inner, intermediate, and outer members 1210, 1220, 1230 also include a respective intermediate portion 1210c, 1220c, 1230c that may be passively bendable and / or flexible (e.g., to accommodate one or more turns in the body lumen) but not steerable. Similar to ML shaft 600, the first and second flexible regions 1218a-b, 1228a-b, 1238a-b may include a plurality of cuts and / or slits in the respective tubular sidewall, such as circumferentially extending cuts and / or helically extending cuts, etc., configured to improve the flexibility and / or bendability of the respective elongate tubular member along that region. Likewise, each of the intermediate portions 1210c, 1220c, 1230c may include a plurality of cuts and / or slits (not shown in FIG. 12), such as circumferentially extending cuts and / or helically extending cuts, etc., configured to improve the flexibility and / or bendability of the respective elongate tubular member along that region. Additional features of the inner, intermediate, and outer members 1210, 1220, 1230 can be generally similar to the inner, intermediate, and outer members 610, 620, 630 described above except as noted herein.

[0099] The first steerable region 1202a can have a first length measured along a longitudinal axis L of the ML shaft 1200 and is configured to bend into a curve up to a maximum radius of curvature of about 5 mm to about 40 mm, 10 mm to about 20 mm, 10 mm to about 30 mm, at least 10 mm, no more than 40 mm, or no more than 30 mm. Having a predefined maximum radius of curvature along the first steerable region 1202a can be beneficial, for example, for following the curvature of the ascending aorta during a transfemoral approach to the aortic valve. FIG. 14, for example, shows a distal portion of a delivery system 100 incorporating the ML shaft 1200 as the middle shaft 120. A securing element (such as securing element 140 or other securing element disclosed herein) can be coupled to the distal end of the shaft (not visible in FIG. 14) for detachably coupling to a prosthetic heart valve 150. The inner shaft 122 (also not visible) may be disposed within a lumen of the ML shaft 1200, and the shaft 900 is disposed within a lumen of the outer shaft 108 and capsule 112. In some embodiments, the first steerable region 1202a has a length of about 30 mm to about 50 mm, or no more than 40 mm.MDT Ref. A0013458W001FortemRef. MDTSH.001WO

[0100] The intermediate member 1220 may include a plurality of first tendons 1226a that extend from the proximal portion 1220a of the intermediate member 1220 to a rigid distal end portion 1224 of the intermediate member 1220. The first tendons 1226a thus extend distally from the proximal portion 1220a, through the intermediate portion 1220c, the second flexible region 1228b, and the first flexible region 1228a. Along at least the intermediate portion 1220c of the intermediate member 1220, the first tendons 1226a may extend linearly (in a linear slot) or helically (in a helical slot). The proximal portions of each of the first tendons 1226a (only one visible in FIG. 12) may be fixedly coupled to a respective slider 1236a. In some embodiments, each of the sliders 1236 may be coupled to an actuation element 106 (directly or via a control interface, such as control interface 650), for controlling axial movement of each of the first tendons 1226a and thus articulation of the first steerable region 1202a. In some cases, the first tendons 1226a may be operatively coupled to rotatable and / or slidable knobs, as discussed above with reference to FIGS. 9B, 10A, 10B, and 11. In some embodiments, the first steerable region 1202a is configured for omni-directional steering and thus includes four first tendons 1226a (as shown). In other embodiments, the first steerable region 1202a is configured for bi-directional steering and thus includes only two first tendons 1226a.

[0101] The second steerable region 1202b can have a second length measured along a longitudinal axis L of the ML shaft 1200 and is configured to bend into a curve up to a maximum radius of curvature of about 10 mm to about 40 mm, or about 20 mm to about 30 mm. Having a predefined maximum radius of curvature along the second steerable region 1202b can be beneficial, for example, for following the curvature in the aortic arch during a transfemoral approach to the aortic valve (as shown in FIG. 14). The second steerable region 1202b can have a length of about 60 mm to about 80 mm, or no more than 80 mm, or no more than 70 mm. The intermediate member 1220 may include a plurality of second tendons 1226b having proximal ends at the proximal portion 1220a of the intermediate member 1220 and distal ends fixed to and / or integral with the rigid portion 1223 between the first and second flexible regions 1228a, 1228b. The second tendons 1226b thus extend through the intermediate portion 1220c and second flexible region 1228b. Along at least the intermediate portion 1220c of the intermediate member 1220, the second tendons 1226b may extend linearly (in a linear slot) or helically (in a helical slot). The proximal portions of each of the second tendons 1226b (not visible in FIG. 12) may be fixedly coupled to a respective slider 1236b associated with the outer member 1230. In some embodiments, each of the sliders 1236b may be coupled to an actuation element 106 (directly or via a control interface, such as control interface 650), forMDT Ref. A0013458W001FortemRef. MDTSH.001WO controlling axial movement of each of the second tendons 1226b and thus articulation of the second steerable region 1202a. In some cases, the second tendons 1226b may be operatively coupled to rotatable and / or slidable knobs, as discussed above with reference to FIGS. 9B, 10A, 10B, and 11. In some embodiments, the second steerable region 1202b is configured for omnidirectional steering and thus includes four second tendons 1226b (as shown). In other embodiments, the second steerable region 1202b is configured for bi-directional steering and thus includes only two second tendons 1226b.

[0102] The first and second steerable regions 1202a, 1202b can have the same or different lengths, and may have the same or different maximum radii of curvature. In some embodiments, the length of the first steerable region 1202a is less than the length of the second steerable region 1202b. In other embodiments, the length of the first steerable region 1202a is greater than the length of the second steerable region 1202b. In some embodiments, the maximum radius of curvature of the first steerable region 1202a is less than the maximum radius of curvature of the second steerable region 1202b. In other embodiments, the maximum radius of curvature of the first steerable region 1202a is greater than the maximum radius of curvature of the second steerable region 1202b.

[0103] In various implementations, the steerable region 1202 can have a length of about 100 mm to about 130 mm, or about 100 mm to about 120 mm, or about 110 mm, or about 111 mm, and can be configured to bend greater than 180 degrees such that the distal tip 132 points back towards the more proximal portion of the catheter portion 102, as shown in FIG. 14. It will be appreciated that other lengths and radii of curvature are possible.

[0104] In some embodiments, the ML shaft 1200 can have an outer diameter of about 3.0 mm to about 4.5 mm, about 3.4 mm to about 4.0 mm, about 3.7 mm, or no less than 3.7 mm. Additionally or alternatively, the ML shaft 1200 can have an inner diameter of about 2.0 mm to about 3.5 mm, about 2.3 mm to about 2.9 mm, about 2.6 mm, or no less than 2.6 mm. The ML shaft 600 can have a total length of from about 1400 to 1500 mm, or about 1450 mm, or no less than 1450 mm.

[0105] As used below, “middle shaft 220” refers to a middle shaft comprising one of the ML shafts described above with reference to FIGS. 6-14, such as ML shaft 600, ML shaft 1200, and all variations mentioned above.

[0106] Another benefit of utilizing an ML shaft (e.g., 600, 1200, etc.) as the middle shaft 120 is the ability to apply rotation to the delivery system. For some heart valve prostheses,MDT Ref. A0013458W001FortemRef. MDTSH.OOIWO it may be beneficial to align the prosthesis in a certain circumferential orientation relative to the native heart valve. During tracking, it may occur that when the delivery system reaches the native heart valve, the prosthesis is not aligned properly and it would be advantageous to rotate the delivery system circumferentially (e.g., about its longitudinal axis) in order to align the prosthesis in a preferred way prior to deployment. By unlocking the actuators, the delivery system may be rotated via rotation of the actuation element (such as a handle) in order to rotate the middle shaft 220, the capsule 112, and the prosthesis 1000 together, while tracked over a guidewire, until the desired orientation is achieved. The components may rotate together due to being rotationally fixed relative to each other at the handle. Controlled rotation, without affecting the angle of the catheter, can be beneficial during deployment of a valve prosthesis as it allows for alignment of the native valve commissures to the prosthetic valve commissures, ensuring the deployment of the valve does not block future access to the coronary arteries.

[0107] FIGS. 15A-15B show an example of rotational alignment of a delivery system incorporating an ML shaft as the middle shaft 120. The delivery system is shown tracked through a model of an aorta A and aortic valve V. To show rotational position, a line 1516 is drawn across the tip 132 and the capsule 112. In FIG. 15A, the line is facing out of the page (toward the reader), or at roughly a 9 o'clock position if looking at a cross-section of the delivery system looking towards the distal end. In FIG. 15B, with the middle shaft 220 in an unlocked state, the actuation element of the delivery system has been rotated, causing the inner, middle, and outer shafts of the delivery system to rotate, as well as the prosthesis held within the capsule. As shown in FIG. 15B, the line 1516 is now facing upwards, or roughly at 12 o'clock.

[0108] Because the tendons are allowed to slide axially in response to bending of the catheter portion 102 (at least in the unlocked state) and thus have the ability to back-drive, there is no whipping of the distal end of the delivery system 200 (e.g., tip 132), but rather the position within the aorta and the aortic valve is stationary except for the rotational movement. This may be due to the lack of energy storage from bending and torque in the middle shaft 220, particularly compared to middle shafts having one or more axial spines that undergo significant compression and tension under tracking and deployment and do not have back-drivable components that allow the shaft to reach a zero stress state. The outer shaft 108 and capsule 112 are configured to work with middle shaft 120 to have this effect. For example, deflectable sections of middle shaft 120 may be matched by an outer shaft length and deflection force to allow middle shaft 120 to perform its desired functions. This tuning can be accomplished, forMDT Ref. A0013458W001FortemRef. MDTSH.OOIWO example, using variable braid properties, various coil designs, and multiple durometer sections. This tuning is important to predictable valve deployment and improved clinical outcomes. As such, the various shafts are designed to work in tandem and not against one another, with the middle shaft undergoing primarily a high tensile force while the outer shaft must withstand high compression forces.

[0109] Having the tendons at least partially unlocked (e.g., one, some, or all unlocked) during deployment may assist in releasing energy from the system during deployment by back-driving the tendons as the prosthesis expands and forces therefrom act on the delivery system. In a delivery system with a middle shaft having a typical shaft construction (i.e., not a multilayer elongate shaft with back-drivable tendons of the present technology), there may be a significant release of energy when the attachment devices of the prosthetic heart valve 1000 are ultimately released from the capsule 112 and the prosthetic heart valve 1000 expands to its fully deployed shape. This may be due to the shape memory properties of the self-expanding prosthetic heart valve 1000. As previously mentioned, use of the middle shaft 220 prevents and / or greatly reduces the storage of torque in the catheter portion 102 and / or middle shaft 220 when twisting and bending forces are applied to the catheter portion 102 and / or middle shaft 220 while the tendons are unlocked. Delivery systems without these features would release shaft energy during deployment, potentially upsetting the final position of the prosthetic heart valve. This large release of energy, particularly at the final stage of deployment, may potentially cause the delivery system to move suddenly which could cause the valve to release and ultimately anchor at a location different than the initial position (e.g., earlier in the deployment process). By allowing some of the energy to be transmitted to the middle shaft 220 and dissipated by back-driving one of more of the tendons, the release of the valve may be less energetic and there may be less movement of the delivery system at final release, thereby facilitating a more predictable and accurate anchoring position of the valve. In at least some embodiments, one, some, or all of the tendons may be unlocked at least during the final deployment of the valve, such as the last 20% of deployment or less (e.g., by length of capsule retraction), last 10% or less of deployment or less, or during release of the attachment devices from the securing element 140. In some embodiments, all middle shaft 220 tendons may be unlocked at this stage to release the most energy.

[0110] FIGS. 16A-16D show an example deployment process for a prosthetic valve 1000 using a delivery system of the present technology, in particular one incorporating an ML shaft (such as any disclosed herein) as the middle shaft. In FIG. 16A, the capsule 112 is in itsMDT Ref. A0013458W001FortemRef. MDTSH.001WO delivery position such that it is fully advanced distally to abut the tip 132 and the valve 1000 is in its constrained configuration held entirely within the capsule 112. The middle shaft 220 is held in a curved delivery state, which may be achieved either by actively steering the middle shaft 220 to a desired bend (e.g., via axial movement of the tendons) or the middle shaft 220 has passively assumed the curved configuration in response to delivery into a curved vessel. The bend 218 shown may simulate a bend used to orient the delivery system in a preferred position once the delivery system is in or near the native aortic valve (or other native valve). For example, it may be advantageous to have the distal end of the delivery system centered in the native valve and / or have the distal end of the delivery system extending parallel to a longitudinal axis of the native valve. This may prevent the prosthesis from being angled or canted relative to the native valve during initial placement and / or upon release. The locking of the middle shaft 220 to thereby hold the catheter in a rigid, curved shape can be beneficial as it prevents the middle shaft 220 from returning to a straight configuration upon valve deployment. This curved to straight energy release can cause valve canting as well.

[0111] With reference to FIG. 16B, the capsule 112 may be partially retracted, for example, by rotating actuator 404 (FIG. 4) to retract the outer shaft 108, which is connected to the capsule 112. Retraction of the capsule 112 exposes a portion of the prosthesis 1000, which may begin to self-expand. Despite proximal movement of the outer shaft 108 and capsule 112, the middle shaft 220 maintains the bend 218, which may allow the orientation within the native valve to be maintained.

[0112] With reference to FIG. 16C, the capsule 112 may be further retracted (e.g., by further rotation of actuator 404), and the prosthesis 1000 continues to expand as more of its length is exposed. With reference to FIG. 16D, the capsule 112 may continue to be retracted beyond the securing element 140, such that attachment devices of the prosthesis 1000 are uncovered and the prosthesis 1000 is completely released and self-expanded. Throughout the deployment of the prosthesis 1000, the bend 218 in the middle shaft 220 can be maintained by keeping the tendons of the middle shaft 220 axially fixed. The ability to move the outer shaft 108 relative to the middle shaft 220 while the latter is in a deflected or articulated position may allow a physician to maintain a preferred position or orientation of the delivery system 200 during deployment.

[0113] In some methods of use, the middle shaft 220 may be at least partially unlocked (i.e., allowing the distal portion to passively bend and flex) for all or a portion of the deployment. For example, once the delivery system has been desirably positioned, some or allMDT Ref. A0013458W001FortemRef. MDTSH.OOIWO of the tendons may be unlocked to allow the middle shaft 220 to back-drive during at least a portion of the deployment process. Alternatively, if the delivery system was able to track to a desired location without locking one or more of the tendons, the tendons may remain unlocked during deployment.

[0114] According to some methods of delivering a prosthetic heart valve to a native heart valve region of a patient, the method comprises introducing an elongate shaft of a delivery device into a femoral blood vessel of the patient with the prosthetic heart valve positioned on the delivery device in a radially compressed state. The elongate shaft may be advanced to a treatment site at a native heart valve region, wherein the elongate shaft is in a flexible configuration during advancement (e.g., the middle shaft is unlocked). For aortic valve procedures, for example, the elongate shaft may be advanced around the aortic arch and into the descending aorta, with the capsule disposed at the native aortic valve. During advancement and / or while positioned at the treatment site, the user may optionally rotate the shaft (as described above) and / or manipulate the actuators to move the tendons and articulate (e.g., steer) the steerable region. In some embodiments the delivery system may be advanced without the use of the steerable region. Once the delivery system and capsule are in a desired position, the actuation element can then be manipulated (e.g., one or more actuators rotated, translated, etc.) to lock the middle shaft and prevent movement of the tendons, thereby causing the elongate shaft to transform from the flexible configuration into the rigid configuration. While the elongate shaft is in the rigid configuration, the outer shaft can be pulled proximally relative to the middle shaft, inner shaft, and prosthetic heart valve such that the outer shaft uncovers the prosthetic heart valve, thereby allowing the prosthetic heart valve to radially self-expand within the native heart valve region. Once the valve is deployed in the native (or existing) valve annulus, the user can manipulate the one or more actuators on the actuation element to unlock the tendons, thereby allowing for axial movement of the tendons and transforming the catheter back into a flexible state for withdrawal from the vasculature.

[0115] FIGS. 17A-18B depict a comparison between (a) deployment by a delivery system 1700 incorporating a middle shaft that is not one of the multi-layer elongate shafts disclosed herein and, (b) deployment by a delivery system 1800 utilizing middle shaft 220. Both delivery systems 1700, 1800 are shown using the same anatomic model. The model used in this example is intended to represent a difficult or challenging anatomy for delivery of a prosthetic valve. FIG. 17A shows the delivery system 1700 at partial deployment of the valve. As shown, the distal end of the delivery system is not oriented on a parallel longitudinal axisMDT Ref. A0013458W001FortemRef. MDTSH.001WO to the model valve annulus, but is rather hugging a wall of the model aorta. As a result, the valve is being initially deployed in an angled or canted orientation relative to the model valve. FIG. 17B shows the valve after full deployment and release of the valve from delivery system 1700. The valve is less canted relative to the model valve that it was during the partial deployment, but there is still some canting that a physician would potentially find undesirable.

[0116] With reference to FIGS. 18A and 18B, delivery of the same valve in the same model is shown using delivery system 1800. As shown in the partial deployment stage of FIG.18 A, the distal end of delivery system 1800 is not hugging the wall of the model aorta, but is instead more centered and extending on an axis more parallel to the model valve. This results in the end of the valve being perpendicular to the longitudinal axis of the model valve and not in an angled or canted position, as compared to FIG. 17 A. Similarly, as shown in FIG. 18 A, the valve maintains the favorable non-canted position in the fully deployed state.

[0117] While the present disclosure primarily refers to use of the multilayer elongate shafts in place of the middle shaft, the multilayer elongate shafts disclosed herein may additionally or alternatively be used in place of the outer shaft 108.EXAMPLES

[0118] The subject technology is illustrated, for example, according to various aspects described above, including with reference to FIGS. 1A-18B. Various examples of aspects of the subject technology are described as numbered examples (1, 2, 3, etc.) for convenience. These are provided as examples and do not limit the subject technology.

[0119] Example 1 : A delivery system, comprising a proximal portion configured to be extracorporeally positioned and a distal portion configured to be positioned at a treatment site proximate a heart valve of a patient; an actuation element at the proximal portion; an elongate member having a proximal region at the actuation element, a distal region configured to be detachably coupled to an implantable device, and a longitudinal axis extending between the proximal and distal regions, wherein the elongate member further includes: an articulable region at the distal region, wherein manipulation of the actuation element causes articulation of the articulable region, a first elongate tube having a flexible region coinciding with the articulable region and a tendon extending longitudinally between the actuation element and the flexible region, the tendon cut from a sidewall that defines the first elongate tube, wherein the tendon is operatively coupled to the actuation element such that manipulation of the actuation element causes axial movement of the tendon, thereby causing articulation of the articulableMDT Ref. A0013458W001FortemRef. MDTSH.OOIWO region, and a second elongate tube coaxial with the first elongate tube and fixed to the first elongate tube at one or more locations; and an outer shaft having a proximal region at the actuation element and a distal region, the shaft defining a lumen therethrough, wherein the elongate member is disposed within the lumen of the outer shaft.

[0120] Example 2: The delivery system of Example 1, wherein the outer shaft is configured to translate longitudinally relative to the elongate member while the elongate member is disposed within the lumen.

[0121] Example 3: The delivery system of Example 2, wherein translation of the outer shaft is caused by manipulation of the actuation element.

[0122] Example 4: The delivery system of any one of Examples 1 to 3, wherein the actuation element is configured to temporarily lock the tendon in a desired axial position thereby preventing articulation of the articulable region.

[0123] Example 5: The delivery system of any one of Examples 1 to 4, wherein the actuation element comprises a handle.

[0124] Example 6: The delivery system of any one of Examples 1 to 4, wherein the actuation element comprises a mechanical interface configured to be coupled to a robotic system.

[0125] Example 7: The delivery system of any one of Examples 1 to 6, wherein the elongate member further comprises a third elongate tube coaxial with the first and second elongate tubes and fixed to one or both of the first and second elongate tubes at one or more locations.

[0126] Example 8: The delivery system of any one of Examples 1 to 7, wherein the second elongate tube comprises a flexible region axially aligned with the flexible region of the first elongate tube such that articulation of the flexible region of the first elongate tube causes articulation of the flexible region of the second elongate tube.

[0127] Example 9: The delivery system of any one of Examples 1 to 8, wherein the articulable region is a first articulable region and the elongate member further comprises a second articulable region at the distal region, and wherein the first articulable region is configured to be articulated independently of the second articulable region, and vice versa.

[0128] Example 10: The delivery system of Example 9, wherein a curve radius of the first articulable region is different than a curve radius of the second articulable region.MDT Ref. A0013458W001FortemRef. MDTSH.OOIWO

[0129] Example 11: The delivery system of Example 9, wherein a length of the first articulable region is different than a length of the second articulable region.

[0130] Example 12: The delivery system of any one of Examples 1 to 11, wherein the articulable region is a first articulable region, the flexible region is a first flexible region, and the tendon is a first tendon, and wherein: the elongate member further comprises a second articulable region, and the first elongate tube comprises a second flexible region axially coinciding with the second articulable region and a second tendon extending longitudinally between the actuation element and the second flexible region, the second tendon cut from the sidewall, wherein the second tendon is configured to transfer a force applied at the actuation element to the second flexible region to cause articulation of the second articulable region.

[0131] Example 13: A delivery system, comprising: a proximal portion configured to be extracorporeally positioned and a distal portion configured to be positioned at a treatment site proximate a heart valve of a patient; an actuation element at the proximal portion; an elongate member having a proximal region at the actuation element, a distal region configured to be detachably coupled to an implantable device, and a longitudinal axis extending between the proximal and distal regions; and an outer shaft having a proximal region at the actuation element and a distal region, the outer shaft defining a lumen therethrough, wherein the elongate member is disposed within the lumen of the outer shaft, and wherein the outer shaft further includes: an articulable region at the distal region of the outer shaft, wherein manipulation of the actuation element causes articulation of the articulable region, a first elongate tube having a flexible region coinciding with the articulable region and a tendon extending longitudinally between the actuation element and the flexible region, the tendon cut from a sidewall that defines the first elongate tube, wherein the tendon is operatively coupled to the actuation element such that manipulation of the actuation element causes axial movement of the tendon, thereby causing articulation of the articulable region, and a second elongate tube coaxial with the first elongate tube and fixed to the first elongate tube at one or more locations.

[0132] Example 14: A delivery system, comprising: a proximal portion configured to be extracorporeally positioned and a distal portion configured to be positioned at a treatment site proximate a heart valve of a patient; an actuation element at the proximal portion; an elongate member having a proximal region at the actuation element, a distal region configured to be detachably coupled to an implantable device, and a longitudinal axis extending between the proximal and distal regions, wherein the elongate member further includes: a first elongate tube including a first locking element, and a second elongate tube coaxially arranged relativeMDT Ref. A0013458W001FortemRef. MDTSH.OOIWO to the first elongate tube, the second elongate tube including a second locking element and a locking tendon, wherein axial movement of the locking tendon in a first direction causes the second locking element to engage the first locking element, thereby transforming at least a portion of the elongate member from a flexible configuration to a rigid configuration, and wherein axial movement of the locking tendon in a second direction, opposite the first direction, causes the second locking element to disengage the first locking element, thereby transforming the at least a portion of the elongate member from the rigid configuration to the flexible configuration; and an outer shaft having a proximal region at the actuation element and a distal region, the outer shaft defining a lumen therethrough, wherein the elongate member is disposed within the lumen of the outer shaft.

[0133] Example 15: The delivery system of Example 14, wherein the locking tendon is a strip cut from a sidewall defining the second elongate tube.

[0134] Example 16: The delivery system of Example 14 or Example 15, wherein the first locking element is cut from a sidewall defining the first elongate tube.

[0135] Example 17: The delivery system of any one of Examples 14 to 16, wherein the second locking element is cut from a sidewall defining the second elongate tube.

[0136] Example 18: The delivery system of any one of Examples 14 to 17, further comprising a steerable region at the distal portion.

[0137] Example 19: The delivery system of Example 18, wherein the second elongate tube further comprises a steering tendon extending from the proximal portion of the delivery system to the steerable region at the distal portion and that is configured to slide axially to cause deflection of the steerable region when the elongate member is in a flexible configuration and when the elongate member is in a rigid configuration.

[0138] Example 20: The delivery system of any one of Examples 14 to 19, wherein the elongate member further comprises a third elongate tube coaxially arranged relative to the first and second elongate tubes.

[0139] Example 21: A delivery system, comprising: a proximal portion configured to be extracorporeally positioned and a distal portion configured to be positioned at a treatment site proximate a heart valve of a patient; an actuation element at the proximal portion; an elongate member having a proximal region at the actuation element, a distal region configured to be detachably coupled to an implantable device, and a longitudinal axis extending between the proximal and distal regions, wherein the elongate member further includes: a first elongateMDT Ref. A0013458W001FortemRef. MDTSH.OOIWO tube having a locking structure and a locking tendon, each cut from a sidewall defining the first elongate tube, a second elongate tube coaxially arranged relative to the first elongate tube and fixed to the first elongate tube at one or more locations, wherein axial movement of the locking tendon in a first direction causes the locking structure to engage, thereby transforming at least a portion of the elongate member from a flexible configuration to a rigid configuration, and wherein axial movement of the locking tendon in a second direction, opposite the first direction, causes the locking structure to disengage, thereby transforming the at least a portion of the elongate member from the rigid configuration to the flexible configuration; and an outer shaft having a proximal region at the actuation element and a distal region, the outer shaft defining a lumen therethrough, wherein the elongate member is disposed within the lumen of the outer shaft.

[0140] Example 22: The delivery system of Example 21, further comprising a steerable region at the distal portion.

[0141] Example 23 : The delivery system of Example 22, wherein the first elongate tube further comprises a steering tendon extending from the proximal portion of the delivery system to the steerable region at the distal portion and that is configured to slide axially to cause deflection of the steerable region when the elongate member is in a flexible configuration and when the elongate member is in a rigid configuration.

[0142] Example 24: The delivery system of any one of Examples 21 to 23, wherein the elongate member further comprises a third elongate tube coaxially arranged relative to the first and second elongate tubes.

[0143] Example 25: A method of delivery a prosthetic heart valve to a native heart valve region of a patient, the method comprising: introducing an elongate shaft of a delivery device into a femoral blood vessel of the patient with the prosthetic heart valve positioned on the delivery device in a radially compressed state, the delivery device further comprising an actuation element coupled to a proximal portion of the elongate shaft, wherein: the elongate shaft comprises an elongate member with the prosthetic heart valve detachably coupled to a distal region of the elongate member, and an outer shaft disposed over the elongate member and prosthetic heart valve; the elongate member comprises a first elongate tube, a second elongate tube arranged coaxially relative to the first elongate tube, a locking structure cut from a sidewall of one or both of the first and second elongate tubes, and a locking tendon cut from a sidewall of one of the first and second elongate tubes; advancing the elongate shaft to aMDT Ref. A0013458W001FortemRef. MDTSH.001WO treatment site at a native heart valve region, wherein the elongate shaft is in a flexible configuration during advancement; manipulating the actuation element to translate the locking tendon relative to the elongate member, thereby causing the locking structure to engage and the elongate shaft to transform into a rigid configuration; and while the elongate shaft is in the rigid configuration, moving the outer shaft proximally relative to the elongate member and prosthetic heart valve such that the outer shaft uncovers the prosthetic heart valve, thereby allowing the prosthetic heart valve to radially self-expand within the native heart valve region.

[0144] Example 26: The method of Example 25, wherein the locking tendon is translated in a first direction and wherein the method further comprises translating the locking tendon in a second direction opposite the first direction, thereby causing the locking structure to disengage and the elongate shaft to transform back into the flexible configuration.

[0145] Example 27: The method of Example 25 or Example 26, wherein the femoral blood vessel is a femoral artery and the method further comprises advancing the elongate shaft from the femoral artery, through an aortic arch of the patient, and to a native aortic heart valve region.

[0146] Example 28: The method of any one of Examples 25 to 27, wherein the femoral blood vessel is a femoral vein and advancing the elongate shaft comprises advancing the elongate shaft from the femoral vein, through an atrial septum, and to a native mitral heart valve region.CONCLUSION

[0147] Although many of the embodiments are described above with respect to systems, devices, and methods for implanting a prosthetic aortic heart valve, the technology is applicable to other applications and / or other approaches, such as implantation of other heart valves and heart valve repair. Moreover, other embodiments in addition to those described herein are within the scope of the technology. Additionally, several other embodiments of the technology can have different configurations, components, or procedures than those described herein. A person of ordinary skill in the art, therefore, will accordingly understand that the technology can have other embodiments with additional elements, or the technology can have other embodiments without several of the features shown and described above with reference to FIGS. 1A-18B.

[0148] The descriptions of embodiments of the technology are not intended to be exhaustive or to limit the technology to the precise form disclosed above. Where the contextMDT Ref. A0013458W001FortemRef. MDTSH.OOIWO permits, singular or plural terms may also include the plural or singular term, respectively. Although specific embodiments of, and examples for, the technology are described above for illustrative purposes, various equivalent modifications are possible within the scope of the technology, as those skilled in the relevant art will recognize. For example, while steps are presented in a given order, alternative embodiments may perform steps in a different order. The various embodiments described herein may also be combined to provide further embodiments.

[0149] As used herein, the terms “generally,” “substantially,” “about,” and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent variations in measured or calculated values that would be recognized by those of ordinary skill in the art.

[0150] Moreover, unless the word “or” is expressly limited to mean only a single item exclusive from the other items in reference to a list of two or more items, then the use of “or” in such a list is to be interpreted as including (a) any single item in the list, (b) all of the items in the list, or (c) any combination of the items in the list. Additionally, the term "comprising" is used throughout to mean including at least the recited feature(s) such that any greater number of the same feature and / or additional types of other features are not precluded. It will also be appreciated that specific embodiments have been described herein for purposes of illustration, but that various modifications may be made without deviating from the technology. Further, while advantages associated with certain embodiments of the technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the technology. Accordingly, the disclosure and associated technology can encompass other embodiments not expressly shown or described herein.

Claims

MDT Ref. A0013458W001FortemRef. MDTSH.OOIWO CLAIMSI / We claim:

1. A delivery system, comprising:a proximal portion configured to be extracorporeally positioned and a distal portion configured to be positioned at a treatment site proximate a heart valve of a patient;an actuation element at the proximal portion;an elongate member having a proximal region at the actuation element, a distal region configured to be detachably coupled to an implantable device, and a longitudinal axis extending between the proximal and distal regions, wherein the elongate member further includes:an articulable region at the distal region, wherein manipulation of the actuation element causes articulation of the articulable region,a first elongate tube having a flexible region coinciding with the articulable region and a tendon extending longitudinally between the actuation element and the flexible region, the tendon cut from a sidewall that defines the first elongate tube, wherein the tendon is operatively coupled to the actuation element such that manipulation of the actuation element causes axial movement of the tendon, thereby causing articulation of the articulable region, anda second elongate tube coaxial with the first elongate tube and fixed to the first elongate tube at one or more locations; andan outer shaft having a proximal region at the actuation element and a distal region, the shaft defining a lumen therethrough, wherein the elongate member is disposed within the lumen of the outer shaft.

2. The delivery system of claim 1, wherein the outer shaft is configured to translate longitudinally relative to the elongate member while the elongate member is disposed within the lumen.MDT Ref. A0013458W001FortemRef. MDTSH.OOIWO 3. The delivery system of claim 2, wherein translation of the outer shaft is caused by manipulation of the actuation element.

4. The delivery system of any one of claims 1 to 3, wherein the actuation element is configured to temporarily lock the tendon in a desired axial position thereby preventing articulation of the articulable region.

5. The delivery system of any one of claims 1 to 4, wherein the actuation element comprises a handle.

6. The delivery system of any one of claims 1 to 4, wherein the actuation element comprises a mechanical interface configured to be coupled to a robotic system.

7. The delivery system of any one of claims 1 to 6, wherein the elongate member further comprises a third elongate tube coaxial with the first and second elongate tubes and fixed to one or both of the first and second elongate tubes at one or more locations.

8. The delivery system of any one of claims 1 to 7, wherein the second elongate tube comprises a flexible region axially aligned with the flexible region of the first elongate tube such that articulation of the flexible region of the first elongate tube causes articulation of the flexible region of the second elongate tube.

9. The delivery system of any one of claims 1 to 8, wherein the articulable region is a first articulable region and the elongate member further comprises a second articulable region at the distal region, and wherein the first articulable region is configured to be articulated independently of the second articulable region, and vice versa.

10. The delivery system of claim 9, wherein a curve radius of the first articulable region is different than a curve radius of the second articulable region.

11. The delivery system of claim 9, wherein a length of the first articulable region is different than a length of the second articulable region.MDT Ref. A0013458W001FortemRef. MDTSH.OOIWO 12. The delivery system of claim 9, wherein the first articulable region is distal of the second articulable region, and wherein a length of the first articulable region is less than a length of the second articulable region.

13. The delivery system of claim 9, wherein the first articulable region is distal of the second articulable region, and wherein a length of the first articulable region is greater than a length of the second articulable region.

14. The delivery system of any one of claims 1 to 8, wherein the articulable region comprises a first portion have a first bending radius of curvature and a second portion having a second bending radius of curvature, the second bending radius of curvature being different than the first bending radius of curvature.

15. The delivery system of claim 1, wherein the articulable region is a first articulable region, the flexible region is a first flexible region, and the tendon is a first tendon, and wherein:the elongate member further comprises a second articulable region, andthe first elongate tube comprises a second flexible region axially coinciding with the second articulable region and a second tendon extending longitudinally between the actuation element and the second flexible region, the second tendon cut from the sidewall, wherein the second tendon is configured to transfer a force applied at the actuation element to the second flexible region to cause articulation of the second articulable region.

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