Transcatheter heart valve prosthesis deployment system with actuation stop mechanism

Abstract

Methods and system for delivering heart valves are disclosed in which a stop inhibits the system from passing beyond the point of no return where further deployment of a collapsed prosthetic heart valve may render it unable to be recaptured. An elongate catheter may include an outer cover configured to cover and uncover a collapsed prosthetic heart valve. The collapsed prosthetic heart valve is biased to expand radially outward as the outer cover uncovers the collapsed prosthetic heart valve. The system may also include a screw shaft and an actuator rotatable about the screw shaft to cause axial translation of a carriage, and thus the connected outer cover. The stop inhibits further rotation of the actuator, and thus further axial translation of the outer cover, and thus further deployment of the collapsed prosthetic heart valve.

Description

TRANSCATHETER HEART VALVE PROSTHESIS DEPLOYMENT SYSTEM WITHACTUATION STOP MECHANISMCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 638,564, filed April 25, 2024, the entire content of which is incorporated herein by reference.TECHNICAL FIELD

[0002] The present technology is generally related to medical devices. More particularly, in embodiments, this disclosure relates to delivery systems and methods for delivering stents, prosthetic heart valves and other implantable medical devices utilizing an actuation stop mechanism.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 life-threatening 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 orconfiguration as the catheter is navigated to and positioned at a target treatment / deployment site.[00051 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. Then, during deployment, the clinician again manipulates the proximal end of the delivery system. In certain procedures such as transcatheter aortic valve implantation (TAVI), deployment of the new valve may reach a “point of no return” where, once surpassed, the clinician is unable to recapture the valve. Therefore, care and attention must be paid when the clinician is approaching this “point of no return” during deployment.SUMMARY

[0006] In an embodiment, a prosthetic heart valve delivery system includes an elongate catheter comprising an outer cover configured to cover and uncover a collapsed prosthetic heart valve, wherein the collapsed prosthetic heart valve is biased to expand radially outward as the outer cover uncovers the collapsed prosthetic heart valve. A screw shaft has a length extending in an axial direction, wherein the screw shaft includes a plurality of channels defined therein. A control handle portion includes an actuator rotatable about the screw shaft and configured such that rotation of the actuator about the screw shaft provides controlled translation of the outer cover relative to the collapsed prosthetic heart valve. The control handle portion includes a button having an outer surface visible from an outside of the control handle, the button being operatively coupled to the actuator such that the screw shaft can translate in the axial direction relative to the button as the actuator rotates about the screw shaft, the button having a tab that engages with the plurality of channels of the screw shaft during the translation of the screw shaft in the axial direction.

[0007] In certain aspects, the plurality of channels includes a first channel and a second channel; the first channel extends in the axial direction; and at least a portion of the second channel is angled relative to the first channel such that the button is configured toextend radially outward through an aperture of the control handle as the tab translates through the second channel.

[0008] In certain aspects, the second channel ends at a wall that defines a stop for inhibiting further translation of the tab through the second channel.[0009 J In certain aspects, the tab is configured to contact the wall upon reaching a predetermined amount of translation through the plurality of channels, wherein the predetermined amount of translation corresponds with a point of no return in which further withdrawal of the outer cover uncovers the collapsed prosthetic heart valve by an amount in which the outer cover cannot re-cover the collapsed prosthetic heart valve.

[0010] In certain aspects, the plurality of channels includes a third channel directly connected to the second channel and extending radially inward from the second channel; and depression of the button radially inward forces the tab to translate radially inward from the second channel and through the third channel.

[0011] In certain aspects, the plurality of channels includes a fourth channel directly connected to the third channel and extending in the axial direction to allow further axial translation of the button once the tab is disposed in the fourth channel.[00121 In certain aspects, the screw shaft defines a ramped surface in the third channel, wherein the ramped surface is inclined in a direction toward the fourth channel.

[0013] In certain aspects, the ramped surface ends at a ledge that inhibits the tab from traveling from the fourth channel directly into the third channel.

[0014] In certain aspects, the screw shaft defines a wall between the fourth channel and the first channel that inhibits the tab from traveling from the first channel directly into the fourth channel.

[0015] In certain aspects, the screw shaft defines a ramped surface in the fourth channel that is inclined in a direction toward the wall.

[0016] In certain aspects, the button includes a flex arm configured to flex radially inward and outward relative to the screw shaft, and wherein the tab extends from a surface of the flex arm.

[0017] In certain aspects, the tab extends radially inward from the surface.

[0018] In certain aspects, the button includes a pair of flex arms, each flex arm disposed on either radial side of the screw shaft, and wherein the tab extends from a surface of at least one of the flex arms.

[0019] According to another embodiment, a prosthetic heart valve delivery system includes an elongate catheter comprising an outer cover configured to cover and uncover a collapsible prosthetic heart valve. The system includes a screw shaft having a length extending in an axial direction, wherein the screw shaft includes a plurality of channels defined therein, wherein one of the channels ends at a wall. The system includes a control handle disposed about the screw shaft and having an aperture extending entirely through a surface thereof, wherein the control handle includes a depressible button depressible within the aperture. The button includes a tab that slides through the plurality of channels as at least a portion of the control handle is rotated relative to the screw shaft, wherein the tab contacts the wall to limit axial translation of the button relative to the screw shaft.

[0020] In certain aspects, the collapsed prosthetic heart valve is biased to expand radially outward as the outer cover uncovers the collapsed prosthetic heart valve; the control handle includes an actuator rotatable about the screw shaft and the screw shaft is operatively coupled to the outer cover such that rotation of the actuator about the screw shaft provides controlled translation of the outer cover relative to the collapsed prosthetic heart valve; and the button is operatively coupled to the actuator such that the screw shaft translates in the axial direction relative to the button as the actuator rotates about the screw shaft.[00 11 In certain aspects, the plurality of channels includes a first channel extending in the axial direction and a second channel extending non-parallel directly from the first channel; and the button is configured to extend radially outward through an aperture of the control handle as the tab translates through the second channel.

[0022] In certain aspects, the wall is located at an end of the second channel; the plurality of channels includes a third channel extending directly from the second channel; and depression of the button in radially inward forces the tab to translate from the second channel and directly into the third channel.

[0023] In certain aspects, the button includes a flex arm configured to flex radially inward and outward relative to the screw shaft, and wherein the tab extends from a surface of the flex arm to enable the tab to flex radially inward and outward as it translates through at least one of the plurality of channels.

[0024] In another embodiment, a method of intravenously delivering a prosthetic heart valve using a prosthetic heart valve delivery system includes: intravenously inserting an elongate catheter into a patient, wherein the elongate catheter includes an outer coverconfigured to cover and uncover a collapsed prosthetic heart valve that is biased to expand radially outward as the outer cover uncovers the collapsed prosthetic heart valve; rotating an actuator about a screw shaft to axially translate the outer cover relative to the collapsed prosthetic heart valve, wherein rotation of the actuator causes an expansion of the collapsed prosthetic heart valve; based on the rotation of the actuator, translating a tab through a plurality of channels formed in the screw shaft, wherein the tab extends from a button that is configured to extend radially outward through a control handle portion of the prosthetic heart valve delivery system; inhibiting the translating of the tab through the plurality of channels via contact between the tab and a wall located at the end of at least one of the plurality of channels; and upon the tab reaching the wall, depressing the button radially inward to pass the tab into another of the plurality of channels where further axial translation of the tab is enabled.

[0025] In certain aspects, the depressing the button forces the tab radially outward across a ramped surface.BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIGS. 1-2 depict illustrations of a delivery system for implantable medical devices, according to an embodiment.

[0027] FIG. 3 is a perspective view of a control handle portion of the delivery system, according to an embodiment. Here, an outer shell of a front grip and a carriage are shown in cross-section to illustrate components within.

[0028] FIG. 4 is a perspective view of a portion of a screw shaft of the delivery system, according to an embodiment.

[0029] FIG. 5 is a perspective view of a button that engages with the screw shaft, according to an embodiment.

[0030] FIG. 6 is another perspective view of a portion of the screw shaft, according to an embodiment.

[0031] FIGS. 7A-7E are cross-sectional views of sequential operation of the delivery system, namely the use of an actuator stopping mechanism, according to an embodiment.

[0032] FIG. 8 is a cross-sectional view similar to FIGS. 7A-7E, showing manipulation of the control handle portion in a reverse direction upon reaching a point of no return to recapture the implantable medical device, according to an embodiment.

[0033] FIG. 9 is a cross-sectional view similar to FIGS. 7A-8, showing manipulation of the control handle portion in a reverse direction during a loading of the implantable medical device, according to an embodiment. 0034] FIG. 10 is a perspective view of a button of the control handle portion, according to an embodiment.

[0035] FIG. 11 is a cross-sectional view of the actuator stopping mechanism utilizing the button of FIG. 10, according to an embodiment.DETAILED DESCRIPTION

[0036] Embodiments of the present disclosure are described herein. It is to be understood, however, that the disclosed embodiments are merely examples and other embodiments can take various and alternative forms. The figures are not necessarily to scale; some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative bases for teaching one skilled in the art to variously employ the embodiments. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures can be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical application. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations.]0037] “A”, “an”, and “the” as used herein refers to both singular and plural referents unless the context clearly dictates otherwise. By way of example, “a processor” programmed to perform various functions refers to one processor programmed to perform each and every function, or more than one processor collectively programmed to perform each of the various functions.

[0038] Directional terms used herein are made with reference to the views and orientations shown in the exemplary figures. A central axis is shown in the figures anddescribed below. Terms such as “outer” and “inner” are relative to the central axis. For example, an “outer” surface means that the surfaces faces away from the central axis, or is outboard of another “inner” surface. Terms such as “radial,” “axial,” “diameter,” “circumference,” etc. also are relative to the central axis. For example, the “axial” direction refers to a direction parallel to a central axis of a stent graft. The terms “front,” “rear,” “upper” and “lower” designate directions in the drawings to which reference is made. 0039] Unless otherwise indicated, for the delivery system the terms “distal” and “proximal” are used in the following description with respect to a position or direction relative to a treating clinician. “Distal” and “distally” are positions distant from or in a direction away from the clinician, and “proximal” and “proximally” are positions near or in a direction toward the clinician. For the stent-graft prosthesis, “proximal” is the portion nearer the heart by way of blood flow path while “distal” is the portion of the stent-graft further from the heart by way of blood flow path.

[0040] The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Although the description is in the context of treatment of a heart valve, the invention may also be used in any other body passageways where it is deemed useful.[00411 FIGS. 1-2 illustrate an example of a delivery system 100 in accordance with an embodiment hereof. This is merely one example of a delivery system; existing components illustrated in FIGS. 1-2 may be removed and / or additional components may be added to the delivery system 100. In view of the description provided herein, the delivery system 100 may be referred to as a prosthetic heart valve delivery system.

[0042] As shown in FIG. 1, the delivery system 100 generally comprises a catheter portion 102, a distal portion 104, and a proximal control handle portion 106 by which the distal portion 104 is effectively controlled. The delivery system 100 also includes an introducer 107 that is configured to slide over portions of the catheter portion 102 (also referred to as an inline sheath). The catheter portion 102 is preferably 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 allows an implantable medical device, e.g., a prosthetic heart valve, to 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 lumenfor introduction of the delivery catheter 102 and the distal end 104 including the implantable medical device to into a patient’s body. The control handle portion 106 preferably controls movements as translated to the distal portion 104 by way of the elongate structure of the catheter portion 102. Manipulation of the control handle portion 106 permits expansion and deployment of the implantable medical device at a desired location, such as a heart valve annulus, and provides for ease in the delivery and withdrawal of the delivery system through a patient’s vasculature.

[0043] As illustrated in FIG. 2, 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 operatively connected with the control handle portion 106 and surrounds one or more inner shafts. In 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, an axial spine, and one or more flexible plastic outer layers, such as Pebax 7233, Pebax 6333, Nylon 12, Vestamid ML24. The outer shaft 108 extends from the control handle portion 106 and facilitates the advancement of the delivery system 100 along a guidewire and through a patient’s vasculature by improving the pushability of the delivery system 100.]0044j While not shown in FIGS. 1-2, the delivery system 100 can include additional shafts or lumens. For example, in addition to the outer shaft 108 being operatively coupled to the control handle portion 106, a middle shaft can be slidingly disposed within the outer shaft 108 and operatively coupled to the control handle portion 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. An inner shaft can be disposed within the middle shaft 120. As with the outer shaft 108, the middle shaft 120 and the inner shaft 122 can each distally extend from within the control handle portion 106. The middle shaft can be concentrically disposed over the inner shaft, which is concentrically disposed over the guidewire.

[0045] The outer shaft 108 is operatively coupled, at a proximal end, with the control handle portion 106 so as to be movable by operation of the handle control portion. For example, as will be described further herein, twisting, rotating, spinning, or other manipulation of the handle portion 106 can cause corresponding axial or radial movementof the outer shaft 108 relative to, for example, a distal tip 114 of the delivery system 100. The outer shaft 108 is also connected with an outer cover 112, also referred to as an outer sheath or capsule. In some embodiments, the outer cover 112 is a separate component that is coupled to the outer shaft 108. In other embodiments, the outer cover 112 is an integrated extension of the outer shaft 108, i.e., the outer cover 112 and outer shaft 108 are one and the same. The outer cover 112 is configured to retain the implantable medical device, e.g., prosthetic heart valve 116, in a radially collapsed configuration for delivery to the desired implantation location. That is, manipulation of the control handle portion 106 controls axial movement of the outer shaft 108 along central longitudinal axis LA, resulting in the longitudinal translational movement of the outer cover 112 proximally away from the distal portion 104, thereby exposing the implantable medical device, e.g., self-expanding prosthetic heart valve 116. Once exposed, the implantable medical device can be spring- biased or have a shape memory to self-expand radially outward beyond the circumferential profile of the outer cover 112. The control handle portion 106 is designed, among other things, for controlling the advancement and the withdrawal of the outer cover 112.

[0046] During deployment of the implantable medical device (such as prosthetic heart valve 116 during transcatheter aortic valve implantation (TAVI)), deployment of the new valve may reach a “point of no return.” For example, the outer cover 112 may be withdrawn to a point where the prosthetic heart valve 116 has expanded to a point where it can no longer be re -constricted again by the outer cover 112 (e.g., recaptured). Once the outer cover 112 has reached this point of no return, the clinician is no longer able to recapture the prosthetic heart valve 116. There is therefore some anxiety when the clinician approaches this point because the clinician does not wish to inadvertently pass the point of no return before they are satisfied with the valve position.

[0047] Therefore, according to embodiments disclosed herein, the control handle portion 106 is provided with an actuator stopping mechanism that forces a stop or otherwise inhibits axial withdrawal of the outer cover 112 when the outer cover 112 has reached an axial location that corresponds to the deployment being at or near the point of no return or another decision point in the deployment process. The actuator stopping mechanism, also referred to as a hard stop or safety lock, serves as a warning to the clinician that he / she has reached the point of no return (or other decision point), allowing the clinician to make any final adjustments and / or confirm the prosthetic valve 116 is suitable before proceeding withthe remainder of the deployment. The actuator stopping mechanism also forces the clinician to actively perform an additional step (e.g., pressing a button) to enable the control handle portion 106 to allow for further retraction of the outer cover 112. This can act as a level of security, preventing the clinician from inadvertently surpassing the point of no return when the clinician does not intend to do so. This can therefore help prevent inadvertent deployment of prosthetic valves in patients’ hearts.

[0048] FIG. 3 illustrates a control handle portion 206 according to an embodiment. The control handle portion 206 includes the functionality of the control handle portion 106 explained above, unless otherwise indicated. In short, manipulation of the control handle portion 206 controls axial movement or withdrawal of the outer shaft 108 and outer cover 112 to thereby allow the self-expanding prosthetic valve 116 to expand and deploy into the patient’s heart.

[0049] The control handle portion 206 includes a front grip 208 and a micro-control actuator, also referred to as a static actuator 210 or simply an actuator. In FIG. 3, the front grip 208 is shown in a perspective cross-sectional view, and the static actuator 210 is shown in a perspective view. The control front grip 208 and the static actuator 210 can be individually grasped and / or manipulated by the clinician during a surgical procedure (e.g., TAVI) for controlling the covering and withdrawing of the outer cover 112 relative to the implantable medical device, e.g., prosthetic heart valve 116. For example, one hand may be placed on the front grip 208 while another hand is placed on the static actuator 210, and manipulation thereof can cause axial retraction of the outer cover 112. The front grip 208 may have a generally elliptical cross-sectional shape, while the static actuator 210 can have a generally circular cross-sectional shape. The difference between these shapes can aid the clinician in feeling the difference between the front grip 208 and the static actuator 210 during deployment. Of course, different cross-sectional shapes (e.g., square, squircle, triangular, etc.) can be used, and the illustrated shapes are merely exemplary. In addition, each of the front grip 208 and static actuator 210 can include one or more gripping features. For example, the static actuator 210 can include ridges 211 arranged circumferentially about the outer surface thereof.

[0050] The functionality of controlling the covering and withdrawing of the outer cover 112 relative to the implantable medical device can be achieved by a rotational movement of the static actuator 210 relative to the front grip 208. Specifically, the staticactuator 210 can be rotatably coupled but axially fixed with the front grip 208 such that they do not move relatively in the axial direction as the static actuator rotates about a screw shaft 212. In embodiments, the static actuator 210 can cause axial translation of the screw shaft 212 by rotation of the static actuator 210. The screw shaft 212 may be contained within the handle 206 and may be operatively coupled to the outer shaft 108 such that they move axially together. Rotation of the static actuator 210 therefore causes axial movement of the outer shaft and the outer cover 112, allowing expansion of the self-expanding prosthetic heart valve 116 when the outer cover 112 is retracted.[0051 | As illustrated in this embodiment, the control handle portion 206 can also include a rear grip 213. Like the front grip 208, the rear grip 213 is shown in FIG. 3 in a perspective cross-sectional view. The rear grip 213 is also axially fixed relative to the front grip 208 and the static actuator 210 such that it does not move relative to either as the static actuator 210 is rotated to axially translate the screw shaft 212. . The static actuator 210 may be prevented from axial movement in any suitable manner. For example, the actuator may be prevented from axial movement by the front grip 208 and / or rear grip 213. Various connections between the front grip 208, micro-control actuator or static actuator 210, and rear grip 213 can be employed for translating rotational movement of the static actuator 210 into axial movement of the screw shaft, without axial movement of the front grip 208 or the rear grip 213.

[0052] The screw shaft 212 is configured to slide axially through the front grip 208 and static actuator 212 due to rotation of the static actuator 212. To facilitate this, the screw shaft 212 can include one or more pairs of diametrically opposed guides, such as guides 214, 216 illustrated in FIGS. 3-4. These guides 214, 216 can be slots or other similar features formed in the outer surface of the screw shaft 212, having a length extending in the axial direction. The guides 214, 216 can be formed on generally planar surfaces ofthe screw shaft 212, such that the overall cross-sectional shape of the screw shaft 212 is an “I” shape, as shown in FIG. 6. The guides 214, 216 and are configured to receive a pin or other type of protrusion (not shown) of the front grip 208, static actuator 210, and / or rear grip 213. The pins or protrusion can engage with a respective one of the guides 214, 216 so as to guide axial translation of the front grip 208 relative to the screw shaft 212 during rotation of the static actuator 210 about the screw shaft 212.

[0053] The control handle portion 206 also includes an actuator stopping mechanism 220, also referred to as a stop assembly, a hard stop, or a safety lock. The actuator stopping mechanism 220 inhibits further rotational movement of the static actuator 210 and axial movement of the screw shaft 212 once the screw shaft 212 has reached an axial position associated with the point of no return (or other decision point). The actuator stopping mechanism 220 includes a button 230 (shown in isolation in FIG. 5) and a plurality of channels 250-256 formed in the screw shaft 212 (shown in isolation in FIGS. 4, 6). As will be described further below, the actuator stopping mechanism 220 is configured to force the button 230 to pop out of a corresponding aperture in the front grip 208 based on the interaction between the button 230 and the channels 250-256; this occurs as the axial position associated with the point of no return is approached.

[0054] Referring to FIGS. 3-6, the button 230 includes an upper base 232. An upper surface 233 of the upper base 232 is visible from the outside of the front grip 208. The upper surface 233 may be coated with a material that differs from a remainder of the upper base 232. The upper base 232 extends radially outward through the aperture when the button 230 is forced radially outward, as will be discussed below. The upper base 232 may have a concave lower surface 234. The lower surface 234 may be curved or shaped to correspond with the curved shape of the threads of the screw shaft 212, allowing the upper base 232 to slide above (i.e., radially outward) the screw shaft 212 as the screw shaft 212 moves in the axial direction.

[0055] Extending from the upper base 232 are a pair of flex arms 236. In the illustrated embodiment, two flex arms 236 are shown on diametrically opposed sides of the screw shaft 212. However, in other embodiments, only one flex arm 236 is provided for interaction with one side of the screw shaft 212. The flex arms 236 (or simply, arms) can bend or flex radially inward toward one another or radially outward away from one another.

[0056] Each flex arm 236 is axially fixed to the front grip 208, and is configured to slide axially along a corresponding side of the screw shaft 212 as the screw shaft 212 moves axially through the front grip 208. To facilitate this, one or each flex arm 236 has a tracking tab 238 extending radially inward therefrom that engage with channels 250-256 formed in the screw shaft 212. The tracking tabs 238 can be diametrically opposed from each other. Each tracking tab 238 can be a protrusion, pin, or the like that extends from a generally planar inner surface 239 of a base of the flex arm 236. The tracking tabs 238 can have alength extending in the axial direction, and a width (shorter than the length) extending in the radial direction.[00571 The plurality of channels 250-256 guide the tracking tabs 238. Each of the channels 250-256 (each of which is described further below) may be guides, tracks, grooves, slots, voids, or the like formed in the screw shaft 212 and sized to receive one of the tracking tabs 238. While the Figures show the channels 250-256 on one side of the screw shaft, it should be understood that the diametrically opposed side of the screw shaft 212 can also include a corresponding plurality of the channels 250-256. The first channel 250 extends in the axial direction such that axial translation of the screw shaft 212 through the front grip 208 causes the tracking tab 238 to move axially along and through the first channel 250. In other words, rotation of the static actuator 210 causes the screw shaft 212 to translate axially such that the stationary tracking tab 238 moves relatively axially through the moving first channel 250 from an initial position (shown in FIG. 7A) to a subsequent position (shown in FIG. 7B).

[0058] Once the tracking tab 238 reaches the end of the first channel 250 (e.g., FIG. 7B), a wall 251 forces the tracking tab 238 to enter the second channel 252. A proximal end of the second channel 252 is directly connected to a distal end of the first channel 250, and the wall 251 is raised (e.g., radially) from a floor of the first channel 250 and second channel 252. The second channel 252 is angled relative to the first channel 250. For example, the second channel 252 can be oriented such that it intersects the first channel 250 at an acute angle. Further axial translation of the screw shaft 212 through the front grip 208 causes the tracking tab 238 to slide upwards through the second channel 252. Since the flex arms 236 are translatable in the radial direction via the channels, the second channel 252 forces the tracking tab 238 upward until it reaches the end of the second channel 252 (e.g., FIG. 7C), which may extend in the axial direction (e.g., parallel to channel 250). This correspondingly causes the button 230 to extend radially outward (pop out) through the aperture of the front grip 208. As the tracking tab 238 enters angled channel 252, the button 230 may begin to move radially outward (e.g., up, as shown) and continue to move outward as tracking tab 238 continues in channel 252 until it reaches the end of channel 252 and is at its maximum outward deflection (e.g., fully popped out). Accordingly, the channel 252 may represent a range of travel during which the button 230 begins, continues, and stops deflecting outward. In one embodiment, this range of travel may represent from 50 to 95 percent of thedeployment (e.g., as determined by total movement of screw shaft 212), or any sub-range therein. For example, channel 252 may represent from 50 to 90 percent, 55 to 90 percent, 55 to 85 percent, 60 to 90 percent, 60 to 85 percent, or 60 or 80 percent of deployment (e.g., channel 252 starts when the valve is 60% deployed and ends when it is 80% deployed).

[0059] At the end of the second channel 252 is a wall 253. The tracking tab 238 contacts the wall 253 when it reaches the end of the second channel 252. This inhibits further axial translation of the screw shaft 212, and therefore also prevents further rotation of the static actuator 210 and further movement (e.g., retraction) of the outer shaft 108 and outer cover 112. Here, it can be said that the control handle portion 206 has reached the point of no return, in which further axial translation of the screw shaft 212 can cause the prosthetic heart valve 116 to reach a point at which it can no longer be captured by the outer cover 112 (or another decision point). As described above, contacting wall 253 at the end of channel 252 may correspond to a certain percentage of deployment, such as from 70 to 95 percent, or any sub-range therein. For example, the point of no return (or decision point) may be at 70 to 90 percent, 75 to 90 percent, 75 to 85 percent, or about 80 percent (e.g., + / - 3 percent).[0060 f Once the clinician has reached the point of no return (or other decision point), the clinician may elect to recapture the prosthetic heart valve 116 into the outer cover 112. This requires a rotation of the static actuator 210 in the reverse direction. Doing so forces the tracking tab 238 back through the second channel 252 and into the first channel 250, as shown by the arrow in FIG. 8. The clinician can than repeat the deployment procedure by rotating the static actuator 210 to advance the tracking tab 238 back toward the second channel 252, as described above with reference to FIGS. 7A-7C.(00611 Alternatively, if the clinician does not desire to recapture the prosthetic heart valve 116 and instead desires to continue beyond the point of no return, the clinician can depress the button 230 radially inward as indicated by the arrow in FIG. 7D. This forces the tracking tab 238 to slide radially inward (e.g., downward, as shown) through the third channel 254 until reaching the fourth channel 256 (e.g., FIG. 7D). At this point, the tracking tab 238 is disengaged and unconstrained from the wall 253, and further advancement of the tracking tab 238 through the fourth channel 256 can continue (e.g., FIG. 7E).

[0062] The third channel 254 can include a ramp or inclined portion 255 that is inclined in a direction leading to the fourth channel 256, as shown in FIG. 4. This providessome resistance to the clinician as the button 230 is being depressed, to guard against an unintended depression of the button 230. However, the flex arms 236 may flex radially outward to allow the tracking tab 238 to slide along the ramp 255. Depression of the button 230 causes the tracking tab 238 to pass over a ledge 257 at the boundary between the third channel 254 and the fourth channel 256. The ledge 257 can be a wall or similar structure that inhibits the tracking tab 238 from passing back from the fourth channel 256 into the third channel 254 once the tracking tab 238 has reached the fourth channel 256. The ledge 257 can therefore be raised (e.g. in the radial direction) compared to a radial floor of the fourth channel 256.100631 The fourth channel 256 can be parallel with the central axis of the control handle portion 206, just like the first channel 250 is; the fourth channel 256 can be parallel with the first channel 250. This facilitates axial translation of the screw shaft 212 such that the control handle portion 206 can be manipulated beyond the point of no return. For example, FIG. 7E shows further advancement of the tracking tab 238 through the fourth channel 256 until 100% deployment of the prosthetic heart valve 116 has occurred.

[0064] In embodiments, a wall 258 can be provided at an axial end of the fourth channel 256. The wall 258 can provide a hard stop to prevent further axial translation of the screw shaft 212 beyond an axial location that corresponds with another milestone in the deployment, such as full deployment or a second point of no return where a further decision is to be made. In the embodiment shown, the control handle portion 206 cannot be manipulated any further, and thus the outer cover 112 cannot be axially withdrawn any further. In other embodiments, additional channels could be incorporated similar to channels 250-256 to allow the screw shaft 212 to continue movement and further retract the outer cover 112.

[0065] After deployment of the prosthetic heart valve 116, the clinician can return the delivery system 100 to its original, preinstalled configuration prior to removal from the patient. In other words, the outer cover 112 can be axially translated back toward the distal tip 114. To do so, the static actuator 210 can be rotated in a reversed direction about the screw shaft 212, forcing the outer cover 112 to move distally. This forces the tracking tab 238 through the fourth channel 256 and directly into the first channel 250 due to their parallel orientation, as indicated by the arrow shown in FIG. 9. The tracking tab 238 need not pass through the second and third channels 252, 254. The fourth channel 256 mayinclude a ramped surface 259 (e.g., FIG. 4) that is inclined in a direction toward the first channel 250, leading to the wall 251. The tracking tab 238 passes over the ramped surface 259 before reaching the first channel 250. The flexibility of the flex arms 236 may allow the tracking tabs 238 to deflect radially outward as they slide over the ramped surface 259. Once the tracking tab 238 is located in the first channel 250, the wall 251 prevents the tracking tab 238 from re-entering the fourth channel 256 directly; the tracking tab 238 must first pass through the second channel 252 and the third channel 254. The delivery system 100 may also be delivered to the operating room without a heart valve loaded therein and with the outer cover 112 in the distal position. In order to load the heart valve, the outer cover 112 may need to be fully retracted (e.g., past the point of no return). As part of the loading process, the outer cover 112 may need to be advanced from the fully retracted / proximal location (e.g., FIG. 7E) to the fully distal location (e.g., FIG. 7A). The above steps of advancing the tracking tab 238 from channel 256 to channel 250 (e.g., FIG. 9) may therefore facilitate loading, as well.

[0066] As described above, the various stop mechanisms may also be used to prevent further deployment past locations other than the point of no return and may correspond to any other decision point in the deployment process. For example, the stop may correspond to an imaging step, a valve check step (e.g., testing valve function before proceeding), a landing zone check (e.g., determining appropriate depth of implantation), or others.

[0067] It should also be understood that while the above disclosure described a static actuator, the actuator can also be a dynamic actuator in that the actuator can translate axially along the screw shaft and relative to the front grip as the actuator is rotated in order to cause axial translation of the outer cover. Here, the button can be provided on the dynamic actuator (as opposed to the front grip) so that the axial translation of the dynamic actuator causes the button to also translate therewith.

[0068] FIG. 10 illustrates an alternative embodiment of button 230’. The button 230’ can include identical or similar structure and function as described in above embodiments unless otherwise stated. FIG. 11 is a cross-sectional view of the actuation stopping mechanism 220, namely wherein the button 230’ has been forced radially outward similar to that shown in FIG. 7C.

[0069] Referring to FIGS. 10-11, each flex arms 236 of the button 230’ can include a backing ramp 260 extending radially outward therefrom. Each backing ramp 260 is tapered such that it becomes more narrow in the direction facing up in Figures, and wider at the bottom. The backing ramps 260 are configured to inhibit or limit the amount of outward flexing of the flex arms 236 as the tracking tab 238 moves through the inclined portion 255 of the third channel 254. In particular, the inclined portion 255 may force the tracking tab 238 (and thus the flex arms 236) to bend radially outward as the button 230’ is depressed; contact between the backing ramp 260 and a corresponding housing ramp 262 (e.g., shown in FIG. 11) inhibits further radial flexing of the flex arms 236.

[0070] The housing ramp 262 can have a tapered or sloped surface that is similar (e.g., parallel) to the backing ramp 260, and similar (e.g., parallel) to the inclined portion 255 of the third channel 254, thus allowing a 1 : 1 movement of the backing ramp 260 as the button 230’ slides down the inclined portion 255 and maintains contact with the housing ramp 262. The housing ramp 262 can be integrally formed as a single unitary structure with in inner surface of the front grip 208. Alternatively, the housing ramp 262 can be separately connected to the inner surface of the front grip 208. As the tracking tab 238 moves through the second channel 252, the distance between the backing ramp 260 and the housing ramp 262 decreases due to the tapered shape of each. Then, when the tracking tab 238 reaches the hard stop at the end of the second channel 252 (e.g., FIG. 7C), the backing ramp 260 and the housing ramp 262 can be in contact. This allows the housing ramp 262 to support the flex arm 236 when the hard stop has been reached. When the button 230’ is depressed radially inwardly and the tracking tab 238 travels along the third channel 254, the backing ramp 260 separates from the housing ramp 262 due to the tapered nature of the surfaces. At the same time, the ramped surface 255 forces the tracking tab 238 outward, but the housing ramp 262 limits the amount of outward flex of the flex arms 236. This can prevent the tracking tab 238 from becoming dislodged or otherwise separated from the channels (e.g., third channel 254) during manipulation.

[0071] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes can be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments can be combined to formfurther embodiments of the invention that may not be explicitly described or illustrated. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics can be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes can include, but are not limited to cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, to the extent any embodiments are described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics, these embodiments are not outside the scope of the disclosure and can be desirable for particular applications. [ 0072} The following examples are illustrative of the techniques described herein.

[0073] Example 1. A prosthetic heart valve delivery system comprising: an elongate catheter comprising an outer cover configured to cover and uncover a collapsed prosthetic heart valve, wherein the collapsed prosthetic heart valve is biased to expand radially outward as the outer cover uncovers the collapsed prosthetic heart valve; a screw shaft having a length extending in an axial direction, wherein the screw shaft includes a plurality of channels defined therein; and a control handle comprising: an actuator rotatable about the screw shaft and configured such that rotation of the actuator about the screw shaft provides controlled translation of the outer cover relative to the collapsed prosthetic heart valve, and a button having an outer surface visible from an outside of the control handle, the button being operatively coupled to the actuator such that the screw shaft can translate in the axial direction relative to the button as the actuator rotates about the screw shaft, the button having a tab that engages with the plurality of channels of the screw shaft during the translation of the screw shaft in the axial direction.

[0074] Example 2. The prosthetic heart valve delivery system of Example 1, wherein: the plurality of channels includes a first channel and a second channel; the first channel extends in the axial direction; and at least a portion of the second channel is angled relative to the first channel such that the button is configured to extend radially outward through an aperture of the control handle as the tab translates through the second channel.

[0075] Example 3. The prosthetic heart valve delivery system of Example 2, wherein the second channel ends at a wall that defines a stop for inhibiting further translation of the tab through the second channel.

[0076] Example 4. The prosthetic heart valve delivery system of Example 3, wherein the tab is configured to contact the wall upon reaching a predetermined amount of translation through the plurality of channels, wherein the predetermined amount of translation corresponds with a point of no return in which further withdrawal of the outer cover uncovers the collapsed prosthetic heart valve by an amount in which the outer cover cannot re-cover the collapsed prosthetic heart valve.

[0077] Example 5. The prosthetic heart valve delivery system of Example 2, wherein: the plurality of channels includes a third channel directly connected to the second channel and extending radially inward from the second channel; and depression of the button radially inward forces the tab to translate radially inward from the second channel and through the third channel.

[0078] Example 6. The prosthetic heart valve delivery system of Example 5, wherein the plurality of channels includes a fourth channel directly connected to the third channel and extending in the axial direction to allow further axial translation of the button once the tab is disposed in the fourth channel.

[0079] Example 7. The prosthetic heart valve delivery system of Example 6, wherein the screw shaft defines a ramped surface in the third channel, wherein the ramped surface is inclined in a direction toward the fourth channel.

[0080] Example 8. The prosthetic heart valve delivery system of Example 7, wherein the ramped surface ends at a ledge that inhibits the tab from traveling from the fourth channel directly into the third channel.

[0081] Example 9. The prosthetic heart valve delivery system of Example 6, wherein the screw shaft defines a wall between the fourth channel and the first channel that inhibits the tab from traveling from the first channel directly into the fourth channel.

[0082] Example 10. The prosthetic heart valve delivery system of Example 9, wherein the screw shaft defines a ramped surface in the fourth channel that is inclined in a direction toward the wall.

[0083] Example 11. The prosthetic heart valve of Example 1, wherein the button includes a flex arm configured to flex radially inward and outward relative to the screw shaft, and wherein the tab extends radially inward from a surface of the flex arm.

[0084] Example 12. The prosthetic heart valve of Example 11, wherein the flex arm includes a backing ramp with a tapered outer surface configured to be supported by a corresponding tapered surface of a housing ramp. 0085] Example 13. The prosthetic heart valve of Example 1, wherein the button includes a pair of flex arms, each flex arm disposed on either radial side of the screw shaft, and wherein the tab extends from a surface of at least one of the flex arms.

[0086] Example 14. A prosthetic heart valve delivery system comprising: an elongate catheter comprising an outer cover configured to cover and uncover a collapsible prosthetic heart valve; a screw shaft having a length extending in an axial direction, wherein the screw shaft includes a plurality of channels defined therein, wherein one of the channels ends at a wall; and a control handle disposed about the screw shaft and having an aperture extending entirely through a surface thereof, wherein the control handle includes a depressible button depressible within the aperture; wherein the button includes a tab that slides through the plurality of channels as at least a portion of the control handle is rotated relative to the screw shaft, wherein the tab contacts the wall to limit axial translation of the button relative to the screw shaft.

[0087] Example 15. The prosthetic heart valve delivery system of Example 14, wherein: the collapsed prosthetic heart valve is biased to expand radially outward as the outer cover uncovers the collapsed prosthetic heart valve, the control handle includes an actuator rotatable about the screw shaft and the screw shaft is operatively coupled to the outer cover such that rotation of the actuator about the screw shaft provides controlled translation of the outer cover relative to the collapsed prosthetic heart valve, and the button is operatively coupled to the actuator such that the screw shaft translates in the axial direction relative to the button as the actuator rotates about the screw shaft.

[0088] Example 16. The prosthetic heart valve delivery system of Example 14, wherein: the plurality of channels includes a first channel extending in the axial direction and a second channel extending non-parallel directly from the first channel; and the button is configured to extend radially outward through an aperture of the control handle as the tab translates through the second channel.

[0089] Example 17. The prosthetic heart valve delivery system of Example 16, wherein: the wall is located at an end of the second channel; the plurality of channels includes a third channel extending directly from the second channel; and depression of the button in radially inward forces the tab to translate from the second channel and directly into the third channel. 0090] Example 18. The prosthetic heart valve delivery system of Example 14, wherein the button includes a flex arm configured to flex radially inward and outward relative to the screw shaft, and wherein the tab extends from a surface of the flex arm to enable the tab to flex radially inward and outward as it translates through at least one of the plurality of channels.

[0091] Example 19. A method of intravenously delivering a prosthetic heart valve using a prosthetic heart valve delivery system, the method comprising: intravenously inserting an elongate catheter into a patient, wherein the elongate catheter includes an outer cover configured to cover and uncover a collapsed prosthetic heart valve that is biased to expand radially outward as the outer cover uncovers the collapsed prosthetic heart valve; rotating an actuator about a screw shaft to axially translate the outer cover relative to the collapsed prosthetic heart valve, wherein rotation of the actuator causes an expansion of the collapsed prosthetic heart valve; based on the rotation of the actuator, translating a tab through a plurality of channels formed in the screw shaft, wherein the tab extends from a button that is configured to extend radially outward through a control handle portion of the prosthetic heart valve delivery system; inhibiting the translating of the tab through the plurality of channels via contact between the tab and a wall located at the end of at least one of the plurality of channels; and upon the tab reaching the wall, depressing the button radially inward to pass the tab into another of the plurality of channels where further axial translation of the tab is enabled.

[9092] Example 20. The method of claim 19, wherein the depressing the button forces the tab radially outward across a ramped surface.

Claims

WHAT IS CLAIMED IS:

1. A prosthetic heart valve delivery system (100) comprising: an elongate catheter (102) comprising an outer cover (112) configured to cover and uncover a collapsed prosthetic heart valve (116), wherein the collapsed prosthetic heart valve is biased to expand radially outward as the outer cover uncovers the collapsed prosthetic heart valve; a screw shaft (212) having a length extending in an axial direction, wherein the screw shaft includes a plurality of channels (250, 252, 254, 256) defined therein; and a control handle (206) comprising: an actuator (210) rotatable about the screw shaft and configured such that rotation of the actuator about the screw shaft provides controlled translation of the outer cover relative to the collapsed prosthetic heart valve, and a button (230, 230’) having an outer surface visible from an outside of the control handle, the button being operatively coupled to the actuator such that the screw shaft can translate in the axial direction relative to the button as the actuator rotates about the screw shaft, the button having a tab (238) that engages with the plurality of channels of the screw shaft during the translation of the screw shaft in the axial direction.

2. The prosthetic heart valve delivery system of claim 1, wherein: the plurality of channels includes a first channel (250) and a second channel (252); the first channel extends in the axial direction; and at least a portion of the second channel is angled relative to the first channel such that the button is configured to extend radially outward through an aperture of the control handle as the tab translates through the second channel.

3. The prosthetic heart valve delivery system of claim 2, wherein the second channel ends at a wall (253) that defines a stop for inhibiting further translation of the tab through the second channel.

4. The prosthetic heart valve delivery system of claim 3, wherein the tab is configured to contact the wall upon reaching a predetermined amount of translation through the plurality of channels, wherein the predetermined amount of translation corresponds with a point of no return in which further withdrawal of the outer cover uncovers the collapsed prosthetic heart valve by an amount in which the outer cover cannot re-cover the collapsed prosthetic heart valve.

5. The prosthetic heart valve delivery system of claim 2, wherein: the plurality of channels includes a third channel (254) directly connected to the second channel and extending radially inward from the second channel; and depression of the button radially inward forces the tab to translate radially inward from the second channel and through the third channel.

6. The prosthetic heart valve delivery system of claim 5, wherein the plurality of channels includes a fourth channel (256) directly connected to the third channel and extending in the axial direction to allow further axial translation of the button once the tab is disposed in the fourth channel.

7. The prosthetic heart valve delivery system of claim 6, wherein the screw shaft defines a ramped surface (255) in the third channel, wherein the ramped surface is inclined in a direction toward the fourth channel.

8. The prosthetic heart valve delivery system of claim 7, wherein the ramped surface ends at a ledge (257) that inhibits the tab from traveling from the fourth channel directly into the third channel.

9. The prosthetic heart valve delivery system of claim 6, wherein the screw shaft defines a wall (251) between the fourth channel and the first channel that inhibits the tab from traveling from the first channel directly into the fourth channel.

10. The prosthetic heart valve delivery system of claim 9, wherein the screw shaft defines a ramped surface (259) in the fourth channel that is inclined in a direction toward the wall.

11. The prosthetic heart valve of any of claims 1 to 10, wherein the button includes a flex arm (236) configured to flex radially inward and outward relative to the screw shaft, and wherein the tab extends radially inward from a surface of the flex arm.

12. The prosthetic heart valve of claim 11, wherein the flex arm includes a backing ramp (260) with a tapered outer surface configured to be supported by a corresponding tapered surface of a housing ramp.

13. The prosthetic heart valve of any of claims 1 to 10, wherein the button includes a pair of flex arms (236), each flex arm disposed on either radial side of the screw shaft, and wherein the tab extends from a surface of at least one of the flex arms.

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