Patent Description:
Prostheses for implantation in blood vessels or other similar organs of the living body are, in general, well known in the medical art. For example, prosthetic vascular stent-grafts constructed of biocompatible materials have been employed to replace or bypass damaged or occluded natural blood vessels. In general, prosthetic vascular stent-grafts typically include a graft anchoring component that operates to hold a tubular graft component of a suitable graft material in its intended position within the blood vessel. Most commonly, the graft anchoring component is one or more radially compressible stents that are radially expanded in situ to anchor the tubular graft component to the wall of a blood vessel or anatomical conduit. Thus, prosthetic vascular stent-grafts are typically held in place by mechanical engagement and friction due to the opposition forces provided by the radially expandable stents. In another example, expandable stents may be deployed without the addition of a covering graft component. Further, prosthetic valves supported by stent structures have also been developed for heart and venous valve replacement.

In general, rather than performing an open surgical procedure that may be traumatic and invasive, prostheses are preferably deployed through a less invasive intraluminal delivery procedure. More particularly, a lumen or vasculature is accessed percutaneously at a convenient and less traumatic entry point, and the prosthesis is routed through the vasculature to the site where the prosthesis is to be deployed. Intraluminal deployment is typically affected using a delivery catheter with coaxial inner and outer tubes arranged for relative axial movement. For example, a self-expanding prosthesis may be compressed and disposed within the distal end of an outer catheter tube. The catheter is then maneuvered, typically routed through a body lumen until the end of the catheter and the prosthesis are positioned at the intended treatment site. The inner member is then held stationary while the outer tube of the delivery catheter is withdrawn. A stop may be utilized to prevent the prosthesis from being withdrawn with the sheath. As the sheath is withdrawn, the prosthesis is released from the confines of the sheath and radially self-expands so that at least a portion of the prosthesis contacts and substantially conforms to a portion of the surrounding interior of the lumen, e.g., the blood vessel wall or anatomical conduit.

Self-expanding prostheses often foreshorten or longitudinally contract during deployment, and such foreshortening may result in difficulty in accurately positioning the self-expanding prosthesis. Embodiments hereof relate to a delivery system that is configured to compensate for the foreshortening of the self-expanding prosthesis during deployment to ensure accurate positioning thereof. <CIT> describes a delivery system comprising an endoluminal device, an outer sheath, a pusher and a linkage.

Embodiments of the present invention relate generally to delivery systems, and, more specifically to a delivery device for percutaneously delivering a self-expanding prosthesis. The delivery device includes a handle having an actuator thereon, an outer sheath including a proximal end operatively coupled to the handle, a pusher shaft slidingly disposed within the outer sheath, and an inner shaft disposed within the pusher shaft. The pusher shaft has a proximal end operatively coupled to the handle. The inner shaft has a distal portion of the inner shaft that is configured to receive a self-expanding prosthesis thereon. The outer sheath and the pusher shaft are configured to simultaneously move in opposing axial directions via actuation of the actuator on the handle.

Embodiments hereof also relate to a system that includes a self-expanding prosthesis configured to foreshorten during deployment thereof and a delivery device configured to percutaneously deliver the self-expanding prosthesis. The delivery device includes a handle having an actuator thereon, an outer sheath including a proximal end coupled to the handle, a pusher shaft slidingly disposed within the outer sheath, and an inner shaft disposed within the pusher shaft. The pusher shaft has a proximal end coupled to the handle and a distal end configured to releasably couple to the self-expanding prosthesis such that the self-expanding prosthesis axially moves therewith. The inner shaft has a distal portion of the inner shaft that is configured to receive a self-expanding prosthesis thereon. The outer sheath and the pusher shaft are configured to simultaneously move in opposing axial directions via actuation of the actuator on the handle to compensate for the foreshortening of the self-expanding prosthesis during deployment.

Embodiments hereof also relate to a method of delivering a self-expanding heart valve prosthesis to a treatment site within the vasculature of a patient using a delivery device comprising an outer sheath, a pusher shaft, and an inner shaft. The delivery device is delivered to the treatment site such that a proximal end of the self-expanding heart valve prosthesis is positioned at an annulus of a native heart valve. The self-expanding heart valve prosthesis is deployed at the annulus of a native heart valve. The self-expanding heart valve prosthesis foreshortens during deployment. The outer sheath is proximally retracted and the pusher shaft is simultaneously distally advanced as the self-expanding heart valve prosthesis is deployed in order to compensate for the foreshortening of the self-expanding heart valve prosthesis.

The accompanying figures, which are incorporated herein, form part of the specification and illustrate embodiments of a delivery system. Together with the description, the figures further explain the principles of and enable a person skilled in the relevant art(s) to make, use, and implant the prosthesis described herein. In the drawings, like reference numbers indicate identical or functionally similar elements.

Specific embodiments of the present invention are now described with reference to the figures, wherein like reference numbers indicate identical or functionally similar elements. 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 the 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 prosthesis "proximal" is the portion nearer the heart by way of blood flow path while "distal" is the portion of the prosthesis further from the heart by way of blood flow path. In addition, the term "self-expanding" is used in the following description with reference to one or more stent structures of the prostheses hereof and is intended to convey that the structures are shaped or formed from a material that can be provided with a mechanical memory to return the structure from a compressed or constricted delivery configuration to an expanded deployed configuration. Non-exhaustive illustrative self-expanding materials include stainless steel, a pseudo-elastic metal such as a nickel titanium alloy or nitinol, various polymers, or a so-called super alloy, which may have a base metal of nickel, cobalt, chromium, or other metal. Mechanical memory may be imparted to a wire or stent structure by thermal treatment to achieve a spring temper in stainless steel, for example, or to set a shape memory in a susceptible metal alloy, such as nitinol. Various polymers that can be made to have shape memory characteristics may also be suitable for use in embodiments hereof to include polymers such as polynorborene, trans-polyisoprene, styrene-butadiene, and polyurethane. As well poly L-D lactic copolymer, oligo caprylactone copolymer and poly cyclo-octine can be used separately or in conjunction with other shape memory polymers.

The following detailed description is merely illustrative in nature and is not intended to limit the invention as claimed. Although the description of the invention is primarily in the context of treatment of a heart valve, the invention may also be used in any body passageway where it is deemed useful. For example, the invention may be used with any self-expanding prosthesis that is configured to foreshorten during deployment and may be used in any body passageway where such self-expanding prosthesis is deemed useful. As used herein, "prosthesis" or "prostheses" may include any prosthesis including one or more self-expanding structures, including but not limited to heart valve prostheses, stents, stent-graft prostheses, uncovered stents, bare metal stents, drug eluting stents, and any self-expanding structure that is configured to foreshorten during deployment.

Embodiments hereof relate to a delivery device with improved positioning accuracy for percutaneously delivering a self-expanding prosthesis. Self-expanding prostheses often foreshorten during deployment. Stated another way, a length of a self-expanding prosthesis in a delivery or compressed configuration is often longer than a length of the self-expanding prosthesis in a deployed or expanded configuration. Such foreshortening may result in difficulty in accurately positioning the self-expanding prosthesis due to the fact that after being positioned at a target location by a clinician, the self-expanding prosthesis may move away from the target location in situ during deployment thereof. Embodiments hereof relate to a delivery system that is configured to compensate for the foreshortening of the self-expanding prosthesis during deployment to ensure accurate positioning thereof. The clinician is not required to adjust the position of the self-expanding prosthesis during deployment, and thus the delivery system reduces reliance on clinician experience and performance. In addition, embodiments of the delivery system described herein reduces the force exerted on the interface between the delivery device and the self-expanding prosthesis since the self-expanding prosthesis is not held stationary at such interface. More particularly, when the self-expanding prosthesis is configured to foreshorten during deployment, a force up to <NUM> N may be exerted on the interface between the delivery device and the self-expanding prosthesis when the self-expanding prosthesis is forced to remain stationary during deployment. However, in embodiments hereof, the self-expanding prosthesis is distally advanced during deployment to compensate for the foreshortening thereof and forces at the interface between the delivery device and the self-expanding prosthesis are reduced or minimized.

The delivery system will be described in more detail with reference to the figures. A delivery system <NUM> includes a self-expanding prosthesis <NUM> configured to foreshorten during deployment thereof and a delivery device <NUM> configured to percutaneously deliver the self-expanding prosthesis <NUM>. More particularly, the delivery system <NUM> is shown in <FIG>, <FIG>, and <FIG> is a side view of the delivery system <NUM>, with an outer sheath <NUM> thereof shown in a delivery configuration in which the outer sheath <NUM> surrounds and constrains the self-expanding prosthesis <NUM> (not shown in <FIG>) in a compressed or delivery configuration. <FIG> is a cross-sectional view taken along line A-A of <FIG>. <FIG> is a perspective view of a distal portion of the delivery system <NUM> in the delivery configuration but with the outer sheath <NUM> not shown for illustrative purposes only. <FIG> is a side view of the delivery system <NUM> after the outer sheath <NUM> has been retracted to allow the prosthesis <NUM> to self-expand to a deployed or expanded configuration. The delivery device <NUM> includes a handle <NUM> having an actuator <NUM> thereon. The components of the handle <NUM> will be described in detail herein with respect to <FIG>.

In addition to the outer sheath <NUM> operatively coupled to the handle <NUM>, the delivery device <NUM> further includes a pusher shaft <NUM> slidingly disposed within the outer sheath <NUM> and operatively coupled to the handle <NUM>, and an inner shaft <NUM> disposed within the pusher shaft <NUM>. The outer sheath <NUM>, the pusher shaft <NUM>, and the inner shaft <NUM> each distally extend from within the handle <NUM>. As will be explained in greater detail herein, the outer sheath <NUM> and the pusher shaft <NUM> are configured to simultaneously move or translate in opposing axial directions along a central longitudinal axis LA of the delivery device <NUM> via actuation of the actuator <NUM> on the handle <NUM> to compensate for the foreshortening of the self-expanding prosthesis <NUM> during deployment. Stated another way, to deploy the self-expanding prosthesis <NUM>, the outer sheath <NUM> is proximally retracted to expose the self-expanding prosthesis <NUM> and the pusher shaft <NUM> is simultaneously distally advanced to push the self-expanding prosthesis <NUM>. The outer sheath <NUM> and the pusher shaft <NUM> are configured to move at different rates such that the pusher shaft <NUM> is configured to distally advance a predetermined distance that compensates for foreshortening of the self-expanding prosthesis <NUM>.

The outer sheath <NUM> has a proximal end <NUM> disposed within the handle <NUM> and a distal end <NUM>. As best shown in <FIG>, the outer sheath <NUM> defines a lumen <NUM> and is slidingly and concentrically disposed over the pusher shaft <NUM>. A distal portion of the outer sheath <NUM> defines a capsule <NUM>. The capsule <NUM> is configured to retain the self-expanding prosthesis <NUM> in a collapsed configuration for delivery to the desired treatment location as will be described in more detail herein. While the capsule <NUM> is described herein as a distal portion of the outer sheath <NUM>, the capsule <NUM> may be a separate component coupled to the distal end of the outer sheath <NUM>. Moreover, although the outer sheath <NUM> is described herein as a single component, this is not meant to limit the design, and the outer sheath <NUM> may include components such as, but not limited to a proximal shaft or other components suitable for the purposes described herein.

The pusher shaft <NUM> has a proximal end <NUM> disposed within the handle <NUM> and a distal end <NUM> disposed inside of the outer sheath <NUM> when the outer sheath <NUM> is disposed over the self-expanding prosthesis <NUM>. The distal end <NUM> of the pusher shaft <NUM> includes a spindle <NUM> which is releasably coupled to an end of the self-expanding prosthesis <NUM> such that the self-expanding prosthesis axially moves with the pusher shaft <NUM>. As best shown on the perspective view of <FIG>, having the outer sheath <NUM> removed for illustrative purposes only, the spindle <NUM> is a tubular component having at least one recess 107A formed on an outer surface thereof that is configured to receive a paddle 107B extending proximally from the self-expanding prosthesis <NUM>. The paddle 107B fits within or mates with the recess 107A of the spindle <NUM> such that the self-expanding prosthesis <NUM> axially moves concurrently with the pusher shaft <NUM>. Although only one recess 107A is visible on <FIG>, it will be understood by one of ordinary skill in the art that the spindle <NUM> may include two or more recesses for receiving a mating paddle of the self-expanding prosthesis <NUM>, such as for example first and second recesses at opposing locations on the spindle <NUM>. As best shown in <FIG>, the pusher shaft <NUM> defines a lumen <NUM> and is concentrically disposed over the inner shaft <NUM>. The inner shaft <NUM> has a proximal end <NUM> proximally extending from the handle <NUM> and a distal end <NUM>. A tapered flexible nosecone or distal tip <NUM> may be coupled to the distal end <NUM> of the inner shaft <NUM> as shown in <FIG>. As best shown in <FIG>, the inner shaft <NUM> defines a lumen <NUM> such that the delivery system <NUM> may be slidingly disposed and tracked over a guidewire <NUM>. The inner shaft <NUM> is coupled to the pusher shaft <NUM> at the spindle <NUM> such that the inner shaft <NUM> and the pusher shaft <NUM> axially move as an assembly.

The inner shaft <NUM> is configured to receive the self-expanding prosthesis <NUM> on a distal portion thereof and the outer sheath <NUM> is configured to compressively retain the self-expanding prosthesis <NUM> on the distal portion of the inner shaft <NUM> during delivery, as shown in <FIG>. Stated another way, the outer sheath <NUM> surrounds and constrains the self-expanding prosthesis <NUM> in a compressed or delivery configuration. As previously described, the distal end <NUM> of the pusher shaft <NUM> includes the spindle <NUM> to which the self-expanding prosthesis <NUM> is releasably coupled. The self-expanding prosthesis <NUM> axially moves with the pusher shaft <NUM>. The self-expanding prosthesis <NUM> is shown in the view of <FIG> but is obscured from view by the outer sheath <NUM> in <FIG>. During deployment of the self-expanding prosthesis <NUM> in situ, the outer sheath <NUM> is proximally retracted with respect to the prostheses <NUM>, thereby incrementally exposing the self-expanding prosthesis <NUM> until the self-expanding prothesis <NUM> is fully exposed and thereby released from the delivery device <NUM>. More particularly, when the outer sheath <NUM> is proximally retracted beyond the spindle <NUM>, the paddles 107B of the self-expanding prosthesis <NUM> are no longer held within the recesses 107A of the spindle and the self-expanding prosthesis <NUM> is permitted to self-expand to its deployed configuration.

<FIG> illustrate side perspective and end views, respectively, of a heart valve prosthesis <NUM> that may be utilized as the self-expanding prosthesis <NUM> according to an embodiment hereof. The heart valve prosthesis <NUM> is merely exemplary and is described in more detail in <CIT> It is understood that any number of alternate heart valve prostheses can be used with the delivery devices and methods described herein. In addition, the delivery device <NUM> may also be used with other self-expanding prostheses such as stent-graft prostheses, uncovered stents, bare metal stents, drug eluting stents, and any self-expanding structure that is configured to foreshorten during deployment.

Heart valve prosthesis <NUM> includes an expandable stent or frame <NUM> that supports a prosthetic valve component <NUM> within the interior of the frame <NUM>. In embodiments hereof, the frame <NUM> is self-expanding to return to an expanded state from a compressed or constricted delivery state. In the embodiment depicted in <FIG>, the frame <NUM> has an expanded, longitudinally asymmetric hourglass configuration including a first end or portion <NUM> and a relatively enlarged second end or portion <NUM>. Each portion of frame <NUM> may be designed with a number of different configurations and sizes to meet the different requirements of the location in which it may be implanted. When configured as a replacement for an aortic valve, as shown for example in <FIG> described in more detail herein, the first end <NUM> functions as an inflow end of the heart valve prosthesis <NUM> and extends into and anchors within the aortic annulus of a patient's left ventricle, while the enlarged second end <NUM> functions as an outflow end of the heart valve prosthesis <NUM> and is positioned in the patient's ascending aorta. When configured as a replacement for a mitral valve, the enlarged second end <NUM> functions as an inflow end of the heart valve prosthesis <NUM> and is positioned in the patient's left atrium, while the first end <NUM> functions as an outflow end of the heart valve prosthesis <NUM> and extends into and anchors within the mitral annulus of a patient's left ventricle. For example, <CIT> and<CIT>, illustrate heart valve prostheses configured for placement in a mitral valve. Each portion of the frame <NUM> may have the same or different cross-portion which may be for example circular, ellipsoidal, rectangular, hexagonal, rectangular, square, or other polygonal shape, although at present it is believed that circular or ellipsoidal may be preferable when the valve prosthesis is being provided for replacement of the aortic or mitral valve. As alternatives to the deployed asymmetric hourglass configuration of <FIG>, the frame <NUM> may have a symmetric hourglass configuration, a generally tubular configuration, or other stent configuration or shape known in the art for valve replacement.

As previously mentioned, the heart valve prosthesis <NUM> includes the prosthetic valve component <NUM> within the interior of frame <NUM>. The prosthetic valve component <NUM> is capable of blocking flow in one direction to regulate flow there through via valve leaflets that may form a bicuspid or tricuspid replacement valve. <FIG> is an end view of <FIG> and illustrates an exemplary tricuspid valve having three leaflets, although a bicuspid leaflet configuration may alternatively be used in embodiments hereof. More particularly, if the heart valve prosthesis <NUM> is configured for placement within a native valve having three leaflets such as the aortic, tricuspid, or pulmonary valves, the heart valve prosthesis <NUM> may include three valve leaflets. If the heart valve prosthesis <NUM> is configured for placement within a native valve having two leaflets such as the mitral valve, the heart valve prosthesis <NUM> may include two valve leaflets. Valve leaflets are sutured or otherwise securely and sealingly attached to the interior surface of the frame <NUM> and/or graft material <NUM> which encloses or lines the frame <NUM> as would be known to one of ordinary skill in the art of prosthetic tissue valve construction. Leaflets are attached along their bases to the graft material <NUM>, for example, using sutures or a suitable biocompatible adhesive. Adjoining pairs of leaflets are attached to one another at their lateral ends to form commissures. The orientation of the leaflets within the frame <NUM> would change depending on which end of the heart valve prosthesis <NUM> is the inflow end and which end of the heart valve prosthesis <NUM> is the outflow end, thereby ensuring one-way flow of blood through the heart valve prosthesis <NUM>.

Leaflets may be made of pericardial material; however, the leaflets may instead be made of another material. Natural tissue for replacement valve leaflets may be obtained from, for example, heart valves, aortic roots, aortic walls, aortic leaflets, pericardial tissue, such as pericardial patches, bypass grafts, blood vessels, intestinal submucosal tissue, umbilical tissue and the like from humans or animals. Synthetic materials suitable for use as leaflets include DACRON® polyester commercially available from Invista North America S. of Wilmington, DE, other cloth materials, nylon blends, polymeric materials, and vacuum deposition nitinol fabricated materials. One polymeric material from which the leaflets can be made is an ultra-high molecular weight polyethylene material commercially available under the trade designation DYNEEMA from Royal DSM of the Netherlands. With certain leaflet materials, it may be desirable to coat one or both sides of the leaflet with a material that will prevent or minimize overgrowth. It is further desirable that the leaflet material is durable and not subject to stretching, deforming, or fatigue.

The graft material <NUM> may also be a natural or biological material such as pericardium or another membranous tissue such as intestinal submucosa. Alternatively, the graft material <NUM> may be a low-porosity woven fabric, such as polyester, Dacron fabric, or PTFE, which creates a one-way fluid passage when attached to the stent. In one embodiment, the graft material <NUM> may be a knit or woven polyester, such as a polyester or PTFE knit, which can be utilized when it is desired to provide a medium for tissue ingrowth and the ability for the fabric to stretch to conform to a curved surface. Polyester velour fabrics may alternatively be used, such as when it is desired to provide a medium for tissue ingrowth on one side and a smooth surface on the other side. These and other appropriate cardiovascular fabrics are commercially available from Bard Peripheral Vascular, Inc. of Tempe, Ariz. , for example.

The heart valve prosthesis <NUM> is designed or configured to have a specific amount of foreshortening or contraction which reduces the length thereof upon radial expansion. Upon radial expansion of the heart valve prosthesis <NUM>, the heart valve prosthesis <NUM> increases in diameter and decreases in length. Stated another way, the heart valve prosthesis <NUM> is configured to foreshorten as the heart valve prosthesis <NUM> transitions between a delivery or compressed configuration to a deployed or expanded configuration.

<FIG> illustrate the shifting or movement in situ of the heart valve prosthesis <NUM> when deployed using a standard delivery system that does not compensate for foreshortening. In <FIG>, a plane representing the native annulus AN is depicted adjacent to the first or inflow end <NUM> of the heart valve prosthesis <NUM>. <FIG> is a side view illustration of the heart valve prosthesis <NUM> in a delivery or compressed configuration, with the first or inflow end <NUM> shown aligned with or positioned at the native annulus AN. Although the heart valve prosthesis <NUM> is shown removed from a delivery device for illustrative purposes only, it will be understood that at this stage of deployment an outer sheath of a standard delivery system is disposed over the entire length of the heart valve prosthesis <NUM> and constrains or compresses the heart valve prosthesis <NUM> into the delivery or compressed configuration.

<FIG> is a side view illustration of the heart valve prosthesis <NUM> in its deployed or expanded configuration after the outer sheath of the standard delivery system is fully proximally retracted to expose the entire length of the heart valve prosthesis <NUM>. As the heart valve prosthesis <NUM> deploys, as shown on <FIG>, it foreshortens or contacts from a first length L1 to a second length L2 and as a result of the foreshortening, the first or inflow end <NUM> of the heart valve prosthesis <NUM> moves away from the native annulus AN such that the heart valve prosthesis <NUM> is spaced apart from its target location by a distance of D1.

The delivery device <NUM> is configured to compensate for the foreshortening of the heart valve prosthesis <NUM> such that the first or inflow end <NUM> is accurately positioned at the native annulus AN. More particularly, distal advancement or movement of the pusher shaft <NUM> during deployment of the heart valve prosthesis <NUM> ensures that the first or inflow end <NUM> of the heart valve prosthesis <NUM> remains positioned at the native annulus AN during deployment. In an embodiment, the heart valve prosthesis <NUM> is configured to foreshorten the distance of D1 during deployment thereof and the pusher shaft <NUM> (the distal end of which is releasably coupled to the heart valve prosthesis <NUM>) is configured to distally advance the heart valve prosthesis <NUM> the same amount, i.e., the distance of D1, during deployment. For example, the heart valve prosthesis <NUM> may be configured to foreshorten a distance of <NUM> during deployment thereof and the pusher shaft <NUM> is then configured to distally advance the heart valve prosthesis <NUM> the distance of <NUM> during deployment to compensate for the foreshortening of the heart valve prosthesis <NUM>.

<FIG> illustrate the transition of the heart valve prosthesis <NUM> when deployed using the delivery system <NUM> that is configured to compensate for foreshortening of the heart valve prosthesis <NUM>. In <FIG>, a plane representing the native annulus AN is depicted adjacent to the first or inflow end <NUM> of the heart valve prosthesis <NUM>. <FIG> is a side view illustration of the heart valve prosthesis <NUM> in a delivery or compressed configuration, with the first or inflow end <NUM> shown aligned with or positioned at the native annulus AN. Although the heart valve prosthesis <NUM> is shown removed from the delivery device <NUM> for illustrative purposes only, it will be understood that at this stage of deployment the outer sheath <NUM> of the delivery system <NUM> is disposed over the entire length of the heart valve prosthesis <NUM> and constrains or compresses the heart valve prosthesis <NUM> into the delivery or compressed configuration.

<FIG> is a side view illustration of the heart valve prosthesis <NUM> in a deployed or expanded configuration after the outer sheath <NUM> of the delivery system <NUM> is fully proximally retracted to expose the entire length of the heart valve prosthesis <NUM>. As the heart valve prosthesis <NUM> deploys, as shown on <FIG>, it foreshortens or contacts from a first length L1 to a second length L2. However, due to the distal advancement of the pusher shaft <NUM>, the first or inflow end <NUM> of the heart valve prosthesis <NUM> remains aligned or positioned at the native annulus AN as shown in <FIG>.

Turning to <FIG> and <FIG>, the handle <NUM> will now be described in more detail. <FIG> is an enlarged cut-away view of the handle <NUM>, while <FIG> is a perspective view of some of the internal components of the handle <NUM>. The handle <NUM> includes the actuator <NUM>, a cap assembly <NUM> having a screw <NUM>, a stationary grip <NUM>, a stationary frame <NUM>, a first carriage <NUM> attached to the proximal end <NUM> of the outer sheath <NUM>, and a second carriage <NUM> attached to the proximal end <NUM> of the pusher shaft <NUM>. The inner shaft <NUM> is disposed through the pusher shaft <NUM> and through a lumen of the screw <NUM>, with the proximal end <NUM> thereof proximally extending outside of the handle <NUM>. As described above, although not shown on <FIG>, the guidewire <NUM> may be slidingly disposed through the inner shaft <NUM>.

The actuator <NUM> is shown in <FIG> as a rotatable housing or shell <NUM>, but may have an alternative configuration as may be understood by one of ordinary skill in the art. The handle <NUM> is configured such that actuation of the actuator <NUM> in a first direction results in the outer sheath <NUM> being proximally retracted and the pusher shaft <NUM> being simultaneously distally advanced. Stated another way, when the rotatable housing <NUM> is rotated in a first or clockwise direction, the outer sheath <NUM> proximally retracts and the pusher shaft <NUM> simultaneously distally advances. Actuation of the actuator <NUM> in a second or opposing direction results in the outer sheath <NUM> being distally advanced and the pusher shaft <NUM> being proximally retracted. Stated another way, when the rotatable housing <NUM> is rotated in a second or counter-clockwise direction, the outer sheath <NUM> distally advances and the pusher shaft <NUM> simultaneously proximally retracts.

As best shown in <FIG>, the rotatable housing <NUM> is a generally tubular structure provided with a threaded interior wall, i.e., a second set of threads <NUM> are formed or disposed on an interior surface thereof which will be described in more detail below. The stationary frame <NUM> is a generally tubular structure that is disposed within the rotatable housing <NUM> and is further fixed or attached to the stationary grip <NUM> disposed at a distal end of the handle <NUM>. The stationary grip <NUM> may include a textured outer surface <NUM> and is configured to be held stationary by the clinician during rotation of the rotatable housing <NUM> and operation of the handle <NUM>. Similarly, the stationary frame <NUM> is fixedly attached to the stationary grip <NUM> and remains stationary during rotation of the rotatable housing <NUM> and operation of the handle <NUM>.

Interaction between the handle <NUM> and the outer sheath <NUM> will be described in more detail with additional reference to <FIG> is another enlarged cut-away view of the handle <NUM> while <FIG> is a perspective view showing the first carriage <NUM> and the stationary frame <NUM> removed from the handle <NUM> for illustrative purposes. <FIG> is a perspective view of only the first carriage <NUM> removed from the handle <NUM> for illustrative purposes. The proximal end <NUM> of the outer sheath <NUM> is disposed within and fixedly attached to the first carriage <NUM> such that the outer sheath <NUM> axially moves with the first carriage <NUM>, which is disposed within the stationary frame <NUM>. The first carriage <NUM> includes a first set of threads <NUM> on an external surface thereof that are configured to mate with the second set of threads <NUM> on an internal surface of the rotatable housing <NUM>. Due to the threaded relationship between the first carriage <NUM> and the rotatable housing <NUM>, and also due to the first carriage <NUM> being prevented from rotating as described in more detail below, the outer sheath <NUM> longitudinally translates with the first carriage <NUM> when the rotatable housing <NUM> is rotated.

More particularly, as best shown in <FIG>, the first carriage <NUM> is provided with a threaded exterior wall, i.e., the first set of threads <NUM> on an exterior surface thereof. The threaded exterior wall of the first carriage <NUM> extends through two opposing slots 165A, 165B of the stationary frame <NUM>. Each slot 165A, 165B is a slot, channel, gap, window, or opening formed in or through a sidewall of the stationary frame <NUM>. As such, the first set of threads <NUM> on the first carriage <NUM> extend or are positioned through the opposing slots 165A, 165B of the stationary frame <NUM> and mate with the second set of threads <NUM> on an interior surface of the rotatable housing <NUM>. Further, with the first carriage <NUM> disposed within the stationary frame <NUM> and the first set of threads <NUM> on the first carriage <NUM> extending or positioned through the opposing slots 165A, 165B of the stationary frame <NUM>, the first carriage <NUM> is prevented from rotating with the rotatable housing <NUM>. Stated another way, the walls of each slot 165A, 165B of the stationary frame <NUM> are disposed adjacent to each side of first set of threads <NUM> on the first carriage <NUM> to prevent rotation of the first carriage <NUM>.

When the rotatable housing <NUM> is rotated, the rotatable housing <NUM> does not axially move due to mechanical engagement with the stationary grip <NUM> and the stationary frame <NUM> attached thereto. More particularly, the stationary grip <NUM> and the stationary frame <NUM> attached thereto are configured to remain stationary during rotation of the rotatable housing <NUM> and operation of the handle <NUM>. When the rotatable housing <NUM> is rotated, the rotatable housing <NUM> spins without translating or moving axially because the rotatable housing <NUM> abuts against the stationary grip <NUM> and the stationary frame <NUM> attached thereto.

When the rotatable housing <NUM> rotates, the thread engagement between the first set of threads <NUM> of the first carriage <NUM> and the second set of threads <NUM> of the rotatable housing <NUM> cause axial movement or translation of the first carriage <NUM> and the outer sheath <NUM> attached thereto. Threads <NUM>, <NUM> are used to convert rotational to translational or linear movement. More particularly, because the first carriage <NUM> is prevented from rotating therewith due to engagement with the walls of each slot 165A, 165B of the stationary frame <NUM> as described above, and because the rotatable housing <NUM> does not axially move due to the stationary grip <NUM> and the stationary <NUM> attached thereto, the rotational movement of the rotatable housing <NUM> and the first carriage <NUM> is converted to translational or linear movement of the first carriage <NUM> due to the threaded relationship between the first carriage <NUM> and the rotatable housing <NUM>.

Interaction between the handle <NUM> and the pusher shaft <NUM> will be described in more detail with additional reference to <FIG> is a perspective view of the cap assembly <NUM> removed from the handle <NUM> for illustrative purposes only, while <FIG> is a perspective view showing the second carriage <NUM> and the cap assembly <NUM> removed from the handle <NUM> for illustrative purposes. <FIG> is an enlarged cut away view of a portion of the handle <NUM>, illustrating the interaction between the second carriage <NUM> and the stationary frame <NUM>. The proximal end <NUM> of the pusher shaft <NUM> is attached to the second carriage <NUM> which is disposed within the stationary frame <NUM>. The second carriage <NUM> includes a third set of threads <NUM> on an internal surface thereof that are configured to mate with a fourth set of threads <NUM> on an external surface of the screw <NUM> of the cap assembly <NUM>. Due to the threaded relationship between the second carriage <NUM> and the cap assembly <NUM>, the pusher shaft <NUM> longitudinally translates with the second carriage <NUM> when the rotatable housing <NUM> is rotated by a clinician.

More particularly, referring to <FIG>, the cap assembly <NUM> includes a cap <NUM> and the screw <NUM> having the fourth set of threads <NUM> formed on an external surface thereof. The cap assembly <NUM> forms the proximal end of the handle <NUM> and is fixedly attached to the rotatable housing <NUM> such that the cap assembly <NUM> rotates therewith. As shown in <FIG>, the second carriage <NUM> includes a second carriage bracket <NUM> and a second carriage retainer <NUM>. The second carriage bracket <NUM> is provided with a threaded interior wall, i.e., the third set of threads <NUM> formed on an internal surface thereof. The third set of threads <NUM> are configured to mate with or engage the fourth set of threads <NUM> formed on the external surface of the screw <NUM>. The second carriage retainer <NUM> is attached to the second carriage bracket <NUM> such that they move in an axial direction as an assembly. The second carriage retainer <NUM> is configured to receive and is fixedly attached to the proximal end <NUM> of the pusher shaft <NUM> such that the pusher shaft <NUM> axially moves with the second carriage retainer <NUM>. Further, the second carriage retainer <NUM> is disposed within the stationary frame <NUM> and the shape thereof is configured to prevent the second carriage <NUM> from rotating with the screw <NUM>. Stated another way, the second carriage retainer <NUM> has a non-circular cross-section that abuts against the internal walls of the stationary frame <NUM> having a circular cross-section to prevent rotation of the second carriage retainer <NUM> therein, and thereby similarly prevent rotation of the second carriage <NUM>.

When the rotatable housing <NUM> is rotated, the cap assembly <NUM> having the screw <NUM> rotates therewith and the thread engagement between the third set of threads <NUM> of the second carriage <NUM> and the fourth set of threads <NUM> of the screw <NUM> cause axial movement or translation of the second carriage <NUM> and the pusher shaft <NUM> attached thereto. Threads <NUM>, <NUM> are used to convert rotational to translational or linear movement. More particularly, because the second carriage <NUM> is prevented from rotating due to engagement of the second carriage retainer <NUM> with the internal walls of the stationary frame <NUM> as described above, the rotational movement of the rotatable housing <NUM>/cap assembly <NUM> and the second carriage <NUM> is converted to translational or linear movement of the second carriage <NUM> due to the threaded relationship between the second carriage <NUM> and the screw <NUM> of the cap assembly <NUM>.

Notably, the first set of threads <NUM> on the first carriage <NUM> are opposingly pitched (i.e., having a different handedness) to the third set of threads <NUM> on the second carriage <NUM> to provide axial translation of the outer sheath <NUM> and the pusher shaft <NUM> in opposing directions. Stated another way, the outer sheath <NUM> and the pusher shaft <NUM> are configured to translate axially in opposing directions since the first set of threads <NUM> on the first carriage <NUM> have an opposite pitch than the third set of threads <NUM> on the second carriage <NUM>. In order for the outer sheath <NUM> and the pusher shaft <NUM> to move in opposing directions via rotation of a single actuator (i.e., the rotate housing <NUM>), the mating threads <NUM>, <NUM> are opposingly pitched (i.e., having a different handedness) to the mating threads <NUM>, <NUM>. When the rotatable housing <NUM> rotates, the thread engagement between the first set of threads <NUM> of the first carriage <NUM> and the second set of threads <NUM> of the rotatable housing <NUM>, and the thread engagement between the third set of threads <NUM> of the second carriage and the fourth set of threads <NUM> of the screw <NUM> of the cap assembly <NUM>, cause axial movement or translation of the outer sheath <NUM> and the pusher shaft <NUM> in opposing or opposite axial directions.

Further, the outer sheath <NUM> and the pusher shaft <NUM> are configured to simultaneously move in opposing axial directions at different rates, with the pusher shaft <NUM> being configured to move at a lower rate than the outer sheath <NUM>. The engaged pairs of threads may include different pitches so that the first carriage <NUM> and the second carriage <NUM> move at different rates. More particularly, the first set of threads <NUM> on the first carriage <NUM> has a first pitch and the third set of threads <NUM> on the second carriage <NUM> has a second pitch. The first pitch of the first set of threads <NUM> is higher than the second pitch of the third set of threads <NUM> such that the pusher shaft <NUM> is configured to move or translate at a lower rate than the outer sheath <NUM>. In an embodiment, the outer sheath <NUM> is configured to move at least <NUM>% faster than the pusher shaft <NUM>. Further, in an embodiment, the pusher shaft <NUM> is configured to advance at a rate profile that corresponds with a rate of foreshortening of the self-expanding prosthesis <NUM>. As described above with respect to <FIG>, the self-expanding prosthesis <NUM> is configured to foreshorten the distance of D1 during deployment thereof and the pusher shaft <NUM> is configured to distally advance the self-expanding prosthesis <NUM> the same amount during deployment. The rate profile of the pusher shaft <NUM> may be configured such that the pusher shaft <NUM> distally advances the self-expanding prosthesis <NUM> the same amount that the self-expanding prosthesis <NUM> foreshortens while the rate profile of the outer sheath <NUM> may be configured to proximally retract the full length of the self-expanding prosthesis <NUM> to fully deploy the self-expanding prosthesis <NUM>. Although the different rates of retraction of the outer sheath <NUM> and advancement of the pusher shaft <NUM> are described herein as being achieved by different pitches of the first set of threads <NUM> and third set of threads <NUM>, this is not meant to be limiting, and other ways to achieve the different rates may also be used.

A method of delivering and deploying the heart valve prosthesis <NUM> with the delivery device <NUM> is depicted in <FIG>. As shown in <FIG>, in accordance with techniques known in the field of interventional cardiology and/or interventional radiology, the delivery system <NUM> including the delivery device <NUM> is transluminally advanced in a retrograde approach through the vasculature to the treatment site, which in this instance is a target diseased native aortic valve AV that extends between a patient's left ventricle LV and a patient's aorta A. Delivery of the delivery system <NUM> to the native aortic valve AV is accomplished via a percutaneous transfemoral approach in which the delivery system is tracked through the femoral artery, up the aorta and around the aortic arch in order to access the native aortic valve AV. The delivery system <NUM> may also be positioned within the desired area of the heart via different delivery methods known in the art for accessing heart valves. As shown, the delivery system <NUM> is tracked over the guidewire <NUM> that has previously been inserted into the patient vasculature. During delivery, as the heart valve prosthesis <NUM> is self-expanding, the heart valve prosthesis <NUM> remains compressed within the capsule <NUM> of the outer sheath <NUM> as the delivery system <NUM> is manipulated and navigated through the vasculature. The delivery system <NUM> is advanced until the distal tip <NUM> thereof is distal to the native aortic valve AV and disposed within the left ventricle LV as shown in <FIG>, such that the first end <NUM> of the heart valve prosthesis <NUM> (which is the inflow and proximal end of the heart valve prosthesis <NUM> when the heart valve prosthesis <NUM> is configured for placement in a native aortic valve) is positioned at an annulus of a native aortic heart valve.

As shown in <FIG>, which is a sectional view of the native aortic heart valve AV, the heart valve prosthesis <NUM> is deployed at the annulus of the native aortic heart valve AV and the heart valve prosthesis <NUM> foreshortens during deployment. During deployment of the heart valve prosthesis <NUM>, the outer sheath <NUM> (and the capsule <NUM> forming the distal portion of the outer sheath <NUM>) is proximally retracted and the pusher shaft <NUM> is simultaneously distally advanced. Because the distal end <NUM> of the pusher shaft <NUM> is releasably coupled to the heat valve prosthesis <NUM>, distal advancement of the pusher shaft <NUM> pushes the heart valve prosthesis <NUM> in order to compensate for the foreshortening of the heart valve prosthesis <NUM>. More particularly, the rotatable housing <NUM> (not shown in <FIG>) is rotated in a first direction (i.e., clockwise) to cause the second carriage <NUM> to translate distally as represented by a directional arrow 1680A and the first carriage <NUM> to translate proximally as represented by a directional arrow 1680B. Movement of the first carriage <NUM> in a proximal direction as represented by the directional arrow 1680B causes the outer sheath <NUM> fixed thereto to move with the first carriage <NUM>. Movement of the second carriage <NUM> in a distal direction as represented by the directional arrow 1680A causes the pusher shaft <NUM> fixed thereto to move with the second carriage <NUM>. Thus, rotation of the rotatable housing <NUM> causes the outer sheath <NUM> to retract proximally while simultaneously causing the pusher shaft <NUM> to advance distally. Distal advancement of the pusher shaft <NUM> as the heart valve prosthesis <NUM> is deployed pushes the outflow or second end <NUM> of the heart valve prosthesis to <NUM> ensure that the inflow or first end <NUM> of the heart valve prosthesis <NUM> remains positioned at the annulus of the native aortic heart valve throughout deployment and further ensures that the inflow or first end <NUM> of the heart valve prosthesis <NUM> is positioned at the annulus of the native aortic heart valve after deployment is complete. When the outer sheath <NUM> is retracted such that all of the heart valve prosthesis <NUM> is uncovered, the heart valve prosthesis <NUM> is released from the pusher shaft <NUM>, for example, by being released from the spindle <NUM> on the distal end <NUM> of the pusher shaft <NUM>. As shown in <FIG>, after deployment of the heart valve prosthesis <NUM> is complete, the delivery device <NUM> is then removed and the heart valve prosthesis <NUM> remains deployed within the native target heart valve.

Claim 1:
A delivery device (<NUM>) for percutaneously delivering a self-expanding prosthesis (<NUM>), the delivery device (<NUM>) comprising:
a handle (<NUM>) having an actuator (<NUM>) thereon;
an outer sheath (<NUM>) including a proximal end operatively coupled to the handle (<NUM>);
a pusher shaft (<NUM>) slidingly disposed within the outer sheath (<NUM>), the pusher shaft (<NUM>) having a proximal end operatively coupled to the handle (<NUM>), wherein a distal end (<NUM>) of the pusher shaft (<NUM>) includes a spindle (<NUM>) which is releasably coupled to an end of the self-expanding prosthesis (<NUM>); and
an inner shaft (<NUM>) disposed within the pusher shaft (<NUM>), the inner shaft (<NUM>) having a distal portion of the inner shaft (<NUM>) that is configured to receive a self-expanding prosthesis (<NUM>) thereon,
wherein the outer sheath (<NUM>) and the pusher shaft (<NUM>) are configured to simultaneously move in opposing axial directions via actuation of the actuator (<NUM>) on the handle (<NUM>), and wherein the inner shaft (<NUM>) is coupled to the pusher shaft (<NUM>) at the spindle (<NUM>) such that the inner shaft (<NUM>) and the pusher shaft (<NUM>) axially move as an assembly.