Patent Description:
The human heart can suffer from various valvular diseases. These valvular diseases can result in significant malfunctioning of the heart and ultimately require repair of the native valve or replacement of the native valve with an artificial valve. There are a number of known repair devices (e.g., stents) and artificial valves, as well as a number of known methods of implanting these devices and valves in humans. Because of the drawbacks associated with conventional open-heart surgery, percutaneous and minimally-invasive surgical approaches are garnering intense attention. In one technique, a prosthetic device is configured to be implanted in a much less invasive procedure by way of catheterization. For example, collapsible transcatheter prosthetic heart valves can be crimped to a compressed state and percutaneously introduced in the compressed state on a catheter and expanded to a functional size at the desired position by balloon inflation or by utilization of a self-expanding frame or stent.

A challenge of implanting a prosthetic valve via a catheterization is control and positioning of the distal end of the delivery apparatus (i.e., the end of the apparatus that is advanced into a patient's heart) and prosthetic valve during the implantation procedure. An additional challenge includes variation in anatomy between patients, which can make some delivery apparatuses or methods unsuitable for patients with particular anatomy. <CIT> discloses a catheter deployment system having a rotation component including a fork attached to a prosthetic mitral valve.

Thus, there is a continuing need for improved transcatheter prosthetic devices and delivery apparatuses for implanting such devices.

Improved prosthetic implant delivery assemblies are disclosed herein, as well as related methods and devices for such assemblies. The disclosed assemblies are configured for delivering replacement heart valves into a heart of a patient.

The present invention relates to a prosthetic implant delivery assembly as defined in independent claim <NUM>. Preferred configurations of the claimed invention are defined in dependent claims <NUM> to <NUM>. In so far as any of the examples described herein are not encompassed by the scope of the claims, they are considered to be as supplementary background information and do not constitute a definition of the claimed invention per se.

In one example of the disclosure, a prosthetic implant delivery assembly can comprise a prosthetic implant comprising an expandable stent portion having a longitudinal axis extending from a first end portion of the stent to a second end portion of the stent, and an elongate catheter having a longitudinal axis extending from a proximal end portion of the catheter to a distal end portion of the catheter and a plurality of arms extending axially from the distal end of the catheter, wherein the first end portion of the stent is releasably and pivotably coupled to at least one the arms of the catheter such that the stent can pivot about the at least one of the arms so that the longitudinal axis of the stent is tilted relative to the longitudinal axis of the catheter.

In some examples, the first end portion of the stent comprises a plurality of apices which are circumferentially-spaced apart relative to each other, each of the arms of the catheter comprises an aperture at a distal end of the arm, and the apices extend through respective apertures of the arms.

In some examples, the delivery assembly further comprises a plurality of elongate locking elements corresponding to the arms of the catheter, wherein each of the apices of the stent comprises a respective opening, and the locking elements are configured to extend through the openings of the apices of the stent, such that the locking elements releasably couple the arms of the catheter to the stent when the apices of the stent are inserted through the apertures of the arms. In some examples, at least one of the locking elements is axially moveable relative to another locking element. In some examples, a length of at least one of the locking elements is different than a length of another locking element.

In some examples, at least one of the apertures of the arms has a different length than another aperture of the arms. In some examples, the catheter further comprises a plurality of sleeves, and the sleeves are configured to be axially slidable relative to a respective aperture of the arms such that the sleeves can be used to alter an effective size of the aperture of the arm, wherein the effective size of the aperture is the portion of the aperture that is unobstructed by the sleeve. In some examples, at least one arms of the catheter is axially moveable relative to another arm. In some examples, a length of at least one arm of the catheter is different than a length of another arm.

In some examples, the delivery assembly is configured for implanting the prosthetic implant to a native aortic valve via a retrograde approach.

In some examples, the longitudinal axis of the stent can tilt up to <NUM> degrees relative to the longitudinal axis of the catheter. In some examples, the longitudinal axis of the stent can tilt from <NUM> degrees to <NUM> degrees relative to the longitudinal axis of the catheter.

According to the invention as defined in claim <NUM>, a prosthetic implant delivery assembly comprises a prosthetic implant comprising an expandable stent portion having a plurality of apices circumferentially spaced around a first end portion of the stent, wherein at least some of the apices comprise an aperture, and an elongate catheter comprising a plurality of radially expandable arms extending axially from a distal end of a shaft of the catheter, each arm having a hook portion which extends radially inwardly, wherein the hook portions of the arms releasably engage a respective aperture of the stent, and the arms of the catheter are configured such that the arms can expand radially relative to the catheter when the arms are exposed from within a sheath such that the hook portions disengage the apertures of the stent.

In some embodiments, the hook portions of the arms extend radially inwardly and are angled proximally.

In some embodiments, the expandable stent is a self-expandable stent. In some embodiments, the expandable arms of the catheter are self-expandable.

In some embodiments, the delivery assembly further comprises a shaft disposed radially within the catheter and an expanding element disposed on a distal end portion the shaft, wherein the expanding element is configured such that relative axial motion between the expanding member and the arms of the catheter in a first direction causes the arms to radially expand and relative axial motion between the expanding member and the arms of the catheter in a second direction allows the arms to radially compress. In some embodiments, the expanding element has a frusto-conical shape.

In some embodiments, the delivery assembly is configured such that relative rotational motion between the shaft and the expanding element causes relative axial motion between the expanding element and the arms of the catheter. In some embodiments, the delivery assembly is configured such that relative axial motion between the shaft and the arms causes relative axial motion between the expanding element and the arms of the catheter.

In some embodiments, the plurality of expandable arms comprises <NUM> to <NUM> arms.

For purposes of this description, certain aspects, advantages, and novel features of the embodiments of this disclosure are described herein. The described methods, systems, and apparatus should not be construed as limiting in any way. Instead, the present disclosure is directed toward all novel and nonobvious features and aspects of the various disclosed embodiments, alone and in various combinations and subcombinations with one another. The disclosed methods, systems, and apparatus are not limited to any specific aspect, feature, or combination thereof, nor do the disclosed methods, systems, and apparatus require that any one or more specific advantages be present or problems be solved.

Features, integers, characteristics, compounds, chemical moieties, or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract, and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract, and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed, as long as it is covered by the appended claims.

Although the operations of some of the disclosed methods are described in a particular, sequential order for convenient presentation, it should be understood that this manner of description encompasses rearrangement, unless a particular ordering is required by specific language set forth below. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed methods, systems, and apparatus can be used in conjunction with other systems, methods, and apparatus.

As used herein, the terms "a," "an," and "at least one" encompass one or more of the specified element. That is, if two of a particular element are present, one of these elements is also present and thus "an" element is present. The terms "a plurality of" and "plural" mean two or more of the specified element.

As used herein, the term "and/or" used between the last two of a list of elements means any one or more of the listed elements. For example, the phrase "A, B, and/or C" means "A," "B," "C," "A and B," "A and C," "B and C," or "A, B, and C.

As used herein, the term "coupled" generally means physically coupled or linked and does not exclude the presence of intermediate elements between the coupled items absent specific contrary language.

Described herein are examples of prosthetic implant delivery assemblies and components thereof which can improve a physician's ability to control the distal end of the delivery assembly during the implantation procedure and which can be used on patients with various anatomies.

For example, in some examples, a delivery assembly can allow a prosthetic valve to be tilted relative to a delivery apparatus so that the prosthetic valve can be deployed coaxially with a native annulus of a heart, even if the delivery apparatus is not coaxial with the native annulus of the heart. In some examples, for example, a delivery assembly can be used to recapture and/or reposition a prosthetic heart valve that has been deployed with a native annulus of a heart.

In some examples, a delivery assembly (e.g., the delivery assembly <NUM> and the delivery assembly <NUM>) is adapted to deliver and implant a prosthetic heart valve in a native aortic annulus or valve of a heart using a retrograde approach (see, e.g., <FIG>), although in other examples it can be adapted to deliver and implant a prosthetic valve in the other native annuluses of the heart (e.g., the pulmonary, mitral, and tricuspid annuluses) and/or to be used with various other approaches (e.g., antegrade, transseptal, transventricular, transatrial, etc.).

A delivery assembly (e.g., the delivery assembly <NUM> and the delivery assembly <NUM>) can also be adapted to deliver and implant a prosthetic valve in other tubular organs or passageways in the body. Further, in addition to prosthetic valves, a delivery assembly can be adapted to deliver and implant various other prosthetic devices such as stents and/or other prosthetic repair devices.

<FIG> shows an example of a prosthetic implant delivery assembly <NUM>, according to one example. The delivery assembly <NUM> can comprise two main components: a prosthetic heart valve <NUM> and a delivery apparatus <NUM>. The prosthetic valve <NUM> can be releasably and pivotably coupled to the delivery apparatus <NUM>, as further described below.

Referring now to <FIG>, the prosthetic valve <NUM> can comprise an annular stent or frame <NUM> and a valve structure <NUM> which is coupled to the frame <NUM>. The prosthetic valve <NUM> can have in inflow end portion <NUM>, and intermediate portion <NUM>, and an outflow end portion <NUM>.

The frame <NUM> can comprise a plurality of interconnected struts <NUM> arranged in a lattice-type pattern and forming a plurality of apices <NUM> at the inflow and outflow ends <NUM>, <NUM> of the prosthetic valve <NUM>. As shown, at least some of the apices <NUM> at the outflow end <NUM> of the prosthetic valve <NUM> can have a respective aperture or opening <NUM> formed therein (e.g., three in the illustrated example). The openings <NUM> can, for example, be used to releasably and pivotably couple the prosthetic valve <NUM> to the delivery apparatus <NUM>, as further explained below (see <FIG>).

The apices <NUM> having the openings <NUM> can be arranged in various ways relative to each other and relative to the other apices <NUM> at the outflow end <NUM> of the prosthetic valve <NUM>. For example, the apices <NUM> having the openings <NUM> can be uniformly (e.g., symmetrically) distributed circumferentially around the outflow end <NUM> of the prosthetic valve <NUM> relative to the other apices <NUM> at the outflow end <NUM> of the prosthetic valve <NUM>. The apices <NUM> with the openings <NUM> can be referred to as connecting arms, or connecting posts, and can be longer than the apices without the openings <NUM>.

The frame <NUM> can be made of any of various suitable plastically-expandable materials (e.g., stainless steel, etc.) or self-expanding materials (e.g., nickel titanium alloy ("NiTi"), such as Nitinol) as known in the art. When constructed of a plastically-expandable material, the frame <NUM> (and thus the prosthetic valve <NUM>) can be crimped to a radially collapsed configuration or state on a delivery catheter and then expanded inside a patient by an inflatable balloon or equivalent expansion mechanism to a functional state. When constructed of a self-expandable material, the frame <NUM> (and thus the prosthetic valve <NUM>) can be crimped to a radially collapsed configuration (see, e.g., <FIG>) and restrained in the collapsed configuration by insertion into a sheath or equivalent mechanism of a delivery catheter. Once inside the body, the prosthetic valve can be advanced from the delivery sheath, which allows the prosthetic valve to radially expand to its functional state (e.g., <FIG>).

Further details regarding the collapsible transcatheter prosthetic heart valves, including the manner in which the valve structure <NUM> can be coupled to the frame <NUM> of the prosthetic valve <NUM> can be found, for example, in <CIT>, <CIT>,<CIT>, <CIT>, and <CIT>.

Referring again to <FIG>, the delivery apparatus <NUM> can comprise a handle <NUM>, an outer catheter <NUM>, a release catheter <NUM>, and a locking catheter <NUM>. The handle <NUM> can be disposed adjacent to a proximal end portion <NUM> of the delivery apparatus <NUM>. The outer catheter <NUM>, the release catheter <NUM>, and the locking catheter <NUM> can extend coaxially along a longitudinal axis <NUM> from the proximal end <NUM> of the delivery apparatus <NUM> toward an opposite, distal end portion <NUM> of the delivery apparatus <NUM>. The release catheter <NUM> and the locking catheter <NUM> can be disposed radially within and extend axially through a lumen of the outer catheter <NUM>. The locking catheter <NUM> can be disposed radially within and extend axially through a lumen <NUM> (see <FIG>) of the release catheter <NUM>.

The outer catheter <NUM>, the release catheter <NUM>, and the locking catheter <NUM> can each be independently moveable relative to each other. In some examples, the delivery apparatus <NUM> can be configured such that relative axial movement between two or more of the catheters <NUM>, <NUM>, <NUM> at the proximal end <NUM> of the delivery apparatus <NUM> can cause corresponding relative axial movement at or near the distal end <NUM> of the delivery apparatus <NUM>. For example, the delivery apparatus <NUM> can be configured such that axially advancing a proximal end of the release catheter <NUM> in the distal direction while maintaining the axial position of the outer catheter <NUM>, and the locking catheter <NUM> causes a distal end of the release catheter <NUM> to axially advance in the distal direction relative to the outer catheter <NUM> and the locking catheter <NUM>.

In an alternative example, the delivery apparatus <NUM> can be configured such that relative rotational movement between two or more of the catheters <NUM>, <NUM>, <NUM> at or near the proximal end of the delivery apparatus <NUM> can cause corresponding relative axial movement at or near the distal end <NUM> of the delivery apparatus <NUM>. For example, the delivery apparatus <NUM> can be configured such that rotating the proximal end of the release catheter <NUM> in a first direction while preventing rotational movement of the outer catheter <NUM> and the locking catheter <NUM> causes the distal end of the release catheter <NUM> to rotate in the first direction relative to the outer catheter <NUM> and the locking catheter <NUM>.

The outer catheter <NUM> can comprise a sheath portion <NUM> disposed at a distal end <NUM> of the outer catheter <NUM>. The sheath <NUM> can be used to retain the prosthetic valve <NUM> in a radially compressed state during delivery of the prosthetic valve <NUM> through a patient's body, as further described below.

Referring now to <FIG>, the release catheter <NUM> can comprise a shaft portion (not shown) and a plurality of tines or arms 150a, 150b, 150c (collectively referred to herein as "the arms <NUM>"). The arms <NUM> can extend axially from a distal end of the shaft and can be spaced apart circumferentially relative to each other. Although the illustrated example shows three arms (e.g., the arms 150a, 150b, 150c) other examples can, for example, have less or more arms (e.g., two, four, five, or six arms). The arms <NUM> of the release catheter <NUM> can each have a respective aperture or window <NUM> disposed near the distal ends <NUM> of the arms <NUM>.

Referring now to <FIG>, the locking catheter <NUM> can, for example, comprise a shaft <NUM> and locking elements or arms 172a, 172b, and 172c (collectively referred to herein as "the arms <NUM>") mounted at a location along the distal end portion of the shaft <NUM>. The arms <NUM> can be spaced apart circumferentially relative to each other. Although the illustrated example shows three arms (e.g., the arms 172a, 172b, 172c) (one locking arm <NUM> for each release arm <NUM>), other examples can, for example, have less or more arms (e.g., two, four, five, or six arms). The arms <NUM> of the locking catheter <NUM> can each have a bent or flared tip portion <NUM> which extends radially outward relative to the rest of the arm <NUM>, as best shown in <FIG>. The flared tip portions <NUM> can facilitate improved interlocking between the apices <NUM> of the prosthetic valve <NUM> and the arms <NUM> of the locking catheter <NUM>, as further described below.

The prosthetic valve <NUM> can be releasably and pivotably coupled to the release catheter <NUM>, for example, by inserting the apices <NUM> of the prosthetic valve <NUM> with the openings <NUM> into respective windows <NUM> of the release catheter <NUM>, as best shown in <FIG>. The apices <NUM> of the prosthetic valve <NUM> can then be releasably secured within the windows <NUM> of the release catheter <NUM> by inserting a respective locking element or arm <NUM> of the locking catheter <NUM> radially between the apices <NUM> of the prosthetic valve <NUM> and the arms <NUM> of the release catheter <NUM> (see <FIG>) and advancing the arms <NUM> of the locking catheter <NUM> axially relative to the prosthetic valve <NUM> and the release catheter <NUM> such that the arms <NUM> of the locking catheter <NUM> extend through the openings <NUM> of the prosthetic valve <NUM>, as best shown in <FIG>.

Coupling the prosthetic valve <NUM> to the release catheter <NUM> in this manner allows the prosthetic valve <NUM> to be released from the release catheter <NUM> by retracting the arms <NUM> proximally relative to the release catheter <NUM> so that the arms <NUM> of the locking catheter withdraw from the openings <NUM> of the prosthetic valve <NUM>, which allows the apices <NUM> of the prosthetic valve <NUM> to slide out of the windows <NUM> of the release catheter <NUM>. Coupling the prosthetic valve <NUM> to the release catheter <NUM> in this manner also allows the prosthetic valve <NUM> to tilt or pivot relative the release catheter <NUM> because the prosthetic valve <NUM> can pivot about the apices <NUM> of the prosthetic valve within the windows <NUM> of the release catheter <NUM>, as further described below.

In some examples, the arms <NUM> of the release catheter <NUM> can be independently axially moveable, relative to each other. For example, as shown in <FIG>, the arms 150a, 150b, and 150c can each be independently axially moveable relative to each other (e.g., in the direction shown by arrows <NUM>). In particular examples, each arm <NUM> can extend axially into the handle <NUM> of the delivery apparatus <NUM> and each arm can be manipulated by a respective actuator (not shown) on or adjacent to the handle <NUM>. In some examples, the proximal end portions of the arms <NUM> can be supported on or coupled to a common shaft that allows independent axial movement of each arm.

Configuring the release catheter <NUM> in this manner allows the release catheter <NUM> to be used to pivot or tilt the prosthetic valve <NUM> relative to the release catheter <NUM> and thus the delivery apparatus <NUM>. For example, as shown in <FIG>, a longitudinal axis <NUM> of the prosthetic valve <NUM> can be aligned with the longitudinal axis <NUM> of the delivery apparatus <NUM> when the arms <NUM> of the release catheter <NUM> are in the same axial position relative to each other. The prosthetic valve <NUM> can be tilted, for example, by moving the arms <NUM> of the release catheter <NUM> axially relative to each other such that the arms <NUM> are not all in the same axial position relative to each other, as shown in <FIG>. This causes the longitudinal axis <NUM> of the prosthetic valve <NUM> to tilt, relative to the longitudinal axis <NUM> of the delivery apparatus <NUM>, toward the arm <NUM> that retracted the farthest (e.g., the arm 150a in <FIG>) such that the axes <NUM>, <NUM> are offset relative to each other by an angle θ.

In some examples, for example, the prosthetic valve <NUM> can be tilted relative to the delivery apparatus <NUM> such that the angle θ is up to <NUM> degrees (e.g., from <NUM> to <NUM> degrees). In other examples, for example, the prosthetic valve <NUM> can be tilted relative to the delivery apparatus such that the angle θ is from <NUM> to <NUM> degrees, from <NUM> to <NUM> degrees, or from <NUM> to <NUM> degrees.

In this manner, the delivery apparatus <NUM> can allow a physician to actively manipulate a prosthetic valve in order to desirably position the prosthetic valve at an implantation site. For example, <FIG> shows one portion of the prosthetic valve <NUM> (e.g., the left side of the prosthetic valve <NUM> in <FIG>) desirably positioned within the native annulus <NUM> and another portion of the prosthetic valve <NUM> (e.g., the right side of the prosthetic valve <NUM> in <FIG>) undesirably positioned within the native annulus <NUM> (e.g., too low in the annulus in <FIG>). To align the prosthetic valve <NUM> with the native annulus <NUM>, the physician can proximally retract (e.g., pull back) one or more of the arms <NUM> (e.g. the rightmost arm(s) <NUM> in <FIG>) of the delivery apparatus <NUM> while maintaining the positioning of one or more of the arms <NUM> (e.g., the leftmost arm(s) <NUM> in <FIG>) of the delivery apparatus <NUM> such that the prosthetic valve tilts (e.g., the right side moves upwardly) relative to the inner catheter <NUM>, as shown in <FIG>.

Additionally, the delivery apparatus <NUM> can allow a prosthetic valve to self-align relative to a native annulus by allowing the prosthetic valve to tilt relative to the delivery apparatus <NUM>. For example, as best shown in <FIG>, the frame <NUM> of the prosthetic valve <NUM> can be configured to have a radially-tapered "waist" portion <NUM> which is disposed between the inflow end <NUM> and the intermediate portion <NUM> of the prosthetic valve <NUM>. The waist portion <NUM> can have a relatively smaller radius than the inflow end <NUM> and the intermediate portion <NUM> of the prosthetic valve <NUM>. As a result, the waist portion <NUM> of the prosthetic valve <NUM> tends to align itself with the native annulus <NUM> when the prosthetic valve <NUM> radially-expands to its functional state and begins to oppose the native leaflets (e.g., the leaflets <NUM>, <NUM>) and the native annulus <NUM>, as best shown, for example, in <FIG>. Accordingly, the prosthetic valve <NUM> can remain coaxial with the delivery apparatus <NUM>, and thus the native annulus <NUM>, if the delivery apparatus <NUM> is coaxial with the native annulus <NUM> when the prosthetic valve <NUM> is deployed; however, the prosthetic valve <NUM> can move proximally and/or tilt so that the prosthetic valve <NUM> is relatively more coaxial with the native annulus <NUM> if the delivery apparatus <NUM> is not coaxial with the native annulus <NUM> when the prosthetic valve <NUM> is deployed (see, e.g., <FIG>).

Although in the illustrated example the outflow end (the proximal end) of the prosthetic valve is releasably coupled to the delivery apparatus, in other examples, the inflow end (the distal end) of the prosthetic valve can be releasably coupled to the delivery apparatus. Also, the orientation of the prosthetic valve can be inverted relative to the delivery apparatus such that the inflow end of the prosthetic valve is the proximal end and the outflow end of the prosthetic valve is the distal end. This can, for example, allow the delivery assembly to be configured for various implantation locations (e.g., the native aortic, pulmonary, mitral, and tricuspid annuluses) and/or for various delivery approaches (e.g., antegrade, transseptal, transventricular, transatrial).

In lieu of or in addition to axially moveable release catheter arms, in some examples, a release catheter <NUM>' can have arms having different axial lengths relative to each other. For example, as shown in <FIG>, an arm 150b' is axially longer than an arm 150a', and an arm 150c' is axially longer than the arms 150a' and 150b'. Configuring the arms <NUM> of the release catheter <NUM>' in this manner causes the prosthetic valve <NUM> to tilt or pivot relative delivery apparatus <NUM> toward the shortest arm <NUM> (e.g., the arm 150a' in <FIG>) at the angle θ when the sheath <NUM> of the delivery apparatus <NUM> is retracted relative to the prosthetic valve <NUM> and the prosthetic valve <NUM> expands to its functional configuration (see, e.g., <FIG>).

In lieu of or in addition to any of the previously described examples, in some examples, a release catheter <NUM>" can have release arms 150a, 150b, 150c having windows that are sized differently relative to each other, as shown in <FIG>. For example, the release catheter <NUM>" comprises a window 170b which is axially longer than windows 170a, 170c. Configuring the windows of the release catheter <NUM>" in this manner allows the prosthetic valve <NUM> to tilt or shift proximally relative delivery apparatus <NUM> toward the longest window (e.g., the window 170b in <FIG>) at the angle θ when the sheath <NUM> of the delivery apparatus <NUM> is retracted relative to the prosthetic valve <NUM> and the prosthetic valve <NUM> expands to its expanded configuration (see, e.g., <FIG>).

The release catheter <NUM>" can also have a plurality of circumferential openings or slots <NUM> which extend axially along a shaft portion <NUM> of the release catheter <NUM>". The slots <NUM> can be configured so as to allow the release catheter <NUM>" to bend relatively more easily in the direction of the slots <NUM>. As such, the release catheter <NUM>" can be formed with the slots <NUM> formed in a first circumferential side portion <NUM> of the shaft <NUM>; whereas, a second circumferential side portion <NUM> (<FIG>) of the shaft <NUM> can be formed without slots. This configuration allows the release catheter <NUM>" to bend relatively more easily toward the first side <NUM> of the shaft <NUM> than toward the second side <NUM> of the shaft <NUM>.

The release catheter <NUM>" can also be configured such that one of the arms of the release catheter <NUM>" can be axially aligned with the side of the shaft <NUM> that has the slots <NUM>. For example, as shown in <FIG>, the arm 150b is axially aligned with the first side <NUM> of the shaft <NUM> which has the slots <NUM>. Aligning one of the arms <NUM> (e.g., the arms 150b) with the relatively more flexible side (e.g., the first side <NUM>) of the shaft <NUM> advantageously allows a physician to predetermine the orientation of the arms <NUM> of the release catheter <NUM>" relative to the patient's native anatomy when the delivery assembly <NUM> is advanced into the patient's body.

For example, when using the delivery assembly <NUM> to deliver the prosthetic valve <NUM> to a native aortic annulus <NUM> of a heart <NUM> using a retrograde approach (e.g., as shown in <FIG>), the release catheter <NUM>" can orient itself such that the slots <NUM> (<FIG>) are adjacent to an inside curved portion <NUM> of an aortic arch <NUM> because the release catheter <NUM>" tends to flex toward the first side <NUM> due to the slots <NUM> in the shaft <NUM>. Thus, because the arm 150b is aligned with the first side <NUM> of release catheter <NUM>", the arm 150b desirably is directed toward the inside curve <NUM> of the aortic arch <NUM>, adjacent to a native left coronary leaflet or cusp <NUM> of the native aortic valve.

In lieu of or in addition to the any of the previously described examples, in some examples, a release catheter <NUM>‴ can have one or more sleeves, each of which is slidably coupled to a respective arm <NUM> of the release catheter <NUM>‴. For example, as shown in <FIG>, the release catheter <NUM>‴ has three sleeves 180a, 180b, 180c (collectively referred to herein as "the sleeves <NUM>") which are slidably coupled to the arms 150a, 150b, 150c, respectively. The sleeves <NUM> can be independently axially slidable both relative to the arms <NUM> and to each other. As such, the sleeves <NUM> can be used to effectively alter the length of windows by axially sliding the sleeves <NUM> relative to a respective window (e.g., in the direction shown by arrow <NUM>).

For example, sliding the sleeve 180b of the release catheter <NUM>‴ proximally relative to the window 170b of the release catheter <NUM>‴ (while maintaining the positioning of the sleeves 180a, 180c relative to the respective windows 170a, 170c) effectively lengthens or extends the window 170b. As such, the window 170b can be effectively longer than the windows 170a, 170c, which allows the prosthetic valve <NUM> to move and/or tilt relative delivery apparatus <NUM> (e.g., at the angle θ) toward the window 170b of the release catheter <NUM>‴ when the sheath <NUM> of the delivery apparatus <NUM> is retracted relative to the prosthetic valve <NUM> and the prosthetic valve <NUM> expands to its functional configuration.

In lieu of or in addition to any of the previously described examples, in some examples, a locking catheter <NUM>' have locking arms that can be independently axially moveable, relative to each other. For example, as shown in <FIG>, the locking catheter <NUM>' can comprise locking arms <NUM> that can each be independently moved axially (e.g., in the direction shown by arrows <NUM>). In particular examples, each locking arm <NUM> can extend axially into the handle <NUM> and each arm can be manipulated by a respective actuator (not shown) on or adjacent the handle. In some examples, the proximal end portions of the arms <NUM> can be supported on or coupled to a common shaft that allows independent movement of each arm.

Configuring the locking catheter <NUM>' in this manner allows the apices <NUM> of the prosthetic valve <NUM> to be released from the delivery apparatus <NUM> simultaneously by retracting the arms <NUM> of the locking catheter <NUM>' proximally relative to the release catheter <NUM> at the same time or sequentially by retracting the arms <NUM> of the locking catheter <NUM>' proximally relative to the release catheter <NUM> at different rates and/or different times relative to each other.

Releasing the apices <NUM> of the prosthetic valve <NUM> from the delivery apparatus <NUM> sequentially can, for example, allow the prosthetic valve <NUM> to tilt relative to the delivery apparatus <NUM>, thereby allowing the prosthetic valve <NUM> to self-align with the native annulus <NUM>, as described above. In addition, releasing one or more of the apices <NUM> of the prosthetic valve <NUM> can allow the physician to actively manipulate the positioning of the prosthetic valve <NUM> relative to the native annulus <NUM> by moving the release catheter <NUM> and/or the arms <NUM> of the release catheter <NUM> that remain attached to the prosthetic value <NUM> axially. This axial movement can cause the prosthetic valve <NUM> to move and/or tilt (e.g., at the angle θ) relative to the delivery apparatus <NUM> and thus relative to the native annulus <NUM>.

In some examples, a locking catheter <NUM>" can have locking arms of different lengths. This can be in lieu of or in addition to the features of any of the previously described examples. For example, as shown in <FIG>, the locking catheter <NUM>" can comprise an arm 172b longer than an arm 172a, and an arm 172c longer than the arms 172a and 172b. Configuring the arms <NUM> of the locking catheter <NUM>" in this manner allows the apices <NUM> of the prosthetic valve <NUM> to be released from the delivery apparatus <NUM> sequentially. This can be accomplished by retracting the locking catheter <NUM>" proximally relative to the release catheter <NUM> such that the arms retract proximally from the openings <NUM> in the apices <NUM> of the prosthetic valve <NUM>. As the locking catheter <NUM> retracts proximally relative to the release catheter <NUM>, the apex <NUM> of the prosthetic valve <NUM> that corresponds to the arm 172a (i.e., the shortest arm) releases from the delivery apparatus <NUM> while the other arms 172b, 172c remain coupled to respective apices <NUM> of the prosthetic valve <NUM>.

Referring to <FIG>, a locking catheter <NUM>" can comprise arms <NUM> extending from a distal end of a main shaft <NUM>'. In this example, the delivery apparatus <NUM> can include a separate shaft that extends co-axially through the shaft <NUM>', with a nose cone <NUM> being mounted on the separate shaft. The main shaft <NUM>' of the locking catheter <NUM>" can have a plurality of circumferential slots <NUM> formed therein. The slots <NUM> can be use as ports, e.g., for an adhesive that is applied the delivery apparatus <NUM> during assembly. The slots <NUM> and/or additional slots (not shown) can be configured to allow the locking catheter <NUM>" to bend more easily toward the first side of the main shaft <NUM>' than towards a second side of the shaft <NUM>' without slots formed therein (e.g., similar to the slots <NUM> formed in the shaft <NUM> of the release catheter <NUM>").

The locking catheter <NUM>" can be configured so that the slots <NUM> circumferentially align with the slots <NUM> of the release catheter <NUM>" when the locking catheter <NUM>" is inserted into and advanced axially through the lumen <NUM> of the release catheter <NUM>. As such, the slots <NUM>, <NUM> of the respective catheters <NUM>, <NUM> can work together to allow the delivery apparatus <NUM> to bend more easily toward the side of the delivery apparatus <NUM> on which the slots <NUM>, <NUM> are disposed.

It should be noted that the release catheters (e.g., release catheter <NUM>") and the locking catheter (e.g., locking catheter <NUM>") can, for example, be formed by laser-cutting respective alloy tubes. The alloy tubes can be formed from various suitable materials including stainless steel, Nitinol, and cobalt chromium.

Releasing one or more of the apices <NUM> of the prosthetic valve while the other apices <NUM> remain attached allows the prosthetic valve <NUM> to self-align with the native annulus (as described above) and/or allows the physician to manipulate the prosthetic valve <NUM> by axially moving the release catheter <NUM> which, in turn, causes the prosthetic valve <NUM> move and/or tilt (e.g., at the angle θ) so that the prosthetic valve <NUM> better aligns with the native annulus <NUM>.

In this manner, the delivery assembly <NUM> can, for example, be oriented within the native aortic annulus <NUM> such that when the prosthetic valve <NUM> is expanded to its functional state the arm 172a of the locking catheter <NUM>" is disposed adjacent to a non-coronary cusp (not shown) and the arms 172b, 172c are respectively disposed adjacent to a right coronary cusp <NUM> and the left coronary cusp <NUM> (see <FIG>). The prosthetic valve <NUM> can then be aligned with the native aortic annulus <NUM> by retracting the locking catheter <NUM> proximally relative to the release catheter <NUM> so that the apex <NUM> of the prosthetic valve <NUM> that corresponds to the arm 172a of the locking catheter <NUM> is released from the delivery apparatus <NUM>. The prosthetic valve <NUM> can then move from a non-aligned and/or non-coaxial positioning (see, e.g., <FIG>) to a relatively more aligned and/or coaxial positioning (see, e.g., <FIG>) by self-aligning relative to the native annulus <NUM> and/or by the physician axially moving the release catheter <NUM> which causes the prosthetic valve <NUM> to move and/or tilt relative to the delivery apparatus <NUM> so that the prosthetic valve <NUM> better aligns with the native annulus <NUM>.

Configuring a delivery assembly so that a prosthetic valve can move and/or tilt relative to a delivery apparatus, for example as described above, can advantageously allow the prosthetic valve to be positioned coaxially or at least more coaxially within a native annulus of a heart in the event that the delivery apparatus cannot achieve the desired coaxiality relative to the native annulus.

For example, <FIG> show an example of a prosthetic valve implantation procedure using the delivery assembly <NUM>. <FIG> shows the delivery assembly <NUM> inserted into a patient's vasculature and the distal end <NUM> of the delivery apparatus <NUM> and the prosthetic valve <NUM> (contained within the sheath <NUM> of the delivery apparatus <NUM> in the compressed configuration) advanced to the native aortic valve annulus <NUM> of the heart <NUM> using a retrograde approach. As shown in <FIG>, the delivery apparatus <NUM> is approximately coaxial with the native aortic annulus <NUM>, but the distal end <NUM> of the delivery apparatus <NUM> extends too deep into the left ventricle <NUM> relative to the native aortic annulus <NUM>. As such, the prosthetic valve <NUM> would be improperly positioned relative to the native annulus <NUM> of the heart <NUM> if the prosthetic valve <NUM> was deployed from within the sheath <NUM> of the delivery apparatus <NUM>. As shown in <FIG>, the distal end <NUM> of the delivery apparatus <NUM> is better positioned relative to the native aortic annulus <NUM> and left ventricle <NUM> than the positioning shown in <FIG>, but the distal end <NUM> of the delivery apparatus <NUM> and thus the prosthetic valve <NUM> would not be coaxial with the native annulus if the prosthetic valve <NUM> was deployed from within the sheath <NUM> of the delivery apparatus <NUM>.

The inability to simultaneously achieve sufficient coaxiality (<FIG>) and proper positioning relative to the native annulus (<FIG>) can be caused by the relatively stiff distal end portion of a delivery assembly which prevents a distal end portion of the delivery apparatus from sufficiently bending so as to be coaxial with the native annulus. The distal end can be relatively stiff compared to other portions of the delivery assembly because of the concentration of material disposed at this portion of the delivery assembly, such as a compressed prosthetic valve and a relatively rigid delivery sheath.

This problem can also be affected by the size of a prosthetic valve in a delivery assembly. For example, a larger prosthetic valve can increase the portion of the delivery assembly that is relatively stiff. For example, a prosthetic valve having a <NUM>-mm diameter can result in a relatively stiff section of about <NUM>, a prosthetic valve having a <NUM>-mm diameter can result in a relatively stiff section of about <NUM>, and a prosthetic valve having a <NUM>-mm diameter can result in a relatively stiff section of about <NUM> (the relatively stiff section being measured from a distal end portion of the sheath toward the proximal end of the delivery apparatus.

In addition, this problem can be compounded by the length of a patient's ascending aorta (e.g., the distance from the aortic arch to the native aortic annulus). For example, a relatively short native ascending aorta provides relatively less room for the delivery apparatus to achieve coaxial alignment before the distal end of the delivery apparatus is disposed too deep into the left ventricle (see, e.g., <FIG>).

Referring now to <FIG>, the prosthetic valve <NUM> can deployed by retracting the outer catheter <NUM> proximally relative to the release catheter <NUM>, which exposes the prosthetic valve <NUM> from within the sheath <NUM>. When the prosthetic valve <NUM> is fully exposed from the sheath <NUM>, the prosthetic valve <NUM> can radially self-expand to its functional state, as shown in <FIG>. Alternatively, although not shown, the prosthetic valve <NUM> can be expanded to its functional state by inflating a balloon portion of the delivery apparatus <NUM> on which the prosthetic valve <NUM> is crimped if the frame <NUM> is formed from a plastically-expandable material.

If the prosthetic valve <NUM> is not coaxial relative to the native aortic annulus <NUM>, for example as shown in <FIG>, then the delivery apparatus <NUM> can be used to move and/or tilt the prosthetic valve <NUM> relative to the delivery apparatus <NUM>, which can improve the coaxiality and/or the positioning of the prosthetic valve <NUM> relative to the native aortic annulus <NUM>, for example as shown in <FIG>. This can be accomplished by using any of the examples and/or techniques described above, including moving the arms <NUM> and/or sleeves <NUM> of the release catheter <NUM>, moving the arms <NUM> of the locking catheter <NUM>, etc..

Once the prosthetic valve <NUM> is desirably positioned within the native annulus <NUM>, the prosthetic valve can be secured within the native annulus and released from the delivery apparatus <NUM>. This can be accomplished by retracting the locking catheter proximally such that all of the arms <NUM> of the locking catheter <NUM> retract from the openings <NUM> in the frame <NUM> of the prosthetic valve <NUM>, thereby releasing the apices <NUM> of the frame <NUM> from the windows <NUM> of the release catheter <NUM>, and thus releasing the prosthetic valve <NUM> from the delivery apparatus <NUM>.

The release catheter <NUM> and the locking catheter <NUM> can then be retracted proximally, such that the release and locking catheters <NUM>, <NUM> are disposed in the outer catheter <NUM> and the nose cone <NUM> of the inner catheter <NUM> is adjacent to the sheath <NUM> of the outer catheter <NUM>. The delivery apparatus <NUM> can then be removed from the patient's body by retracting the delivery apparatus <NUM> proximally.

In another example, the delivery apparatus <NUM> can include a rotatable torque shaft that extends coaxially through the release catheter <NUM> and a sheath that is mounted on the distal end of the torque shaft. The sheath is operatively coupled to the torque shaft such that rotation of the torque shaft is effective to retract or advance the sheath relative to the implant. Further details of the delivery apparatus are disclosed in <CIT>.

<FIG> shows a prosthetic implant delivery assembly <NUM>, according to an embodiment. The delivery assembly <NUM> can comprise two main components: a prosthetic heart valve <NUM> and a delivery apparatus <NUM>. The prosthetic valve <NUM> can be releasably coupled to the delivery apparatus <NUM>, as further described below.

The prosthetic valve <NUM> can have an annular stent or frame <NUM>. Although the frame <NUM> of the prosthetic valve <NUM> is annular, for purposes of illustration, only a partial annular portion of the frame <NUM> is shown for clarity. Also, although the prosthetic valve <NUM> can also have a valve structure disposed radially within and coupled to the frame <NUM> (e.g., in a manner similar to the prosthetic valve <NUM>), for purposes of illustration, the valve structure of the prosthetic valve <NUM> is not shown for clarity.

The frame <NUM> of the prosthetic valve <NUM> can have an inflow end portion <NUM>, an intermediate portion <NUM>, and an outflow end portion <NUM>. The frame <NUM> can also have a plurality of interconnected struts <NUM> arranged in a lattice-type pattern and forming a plurality of apices <NUM>, <NUM> at the respective ends <NUM>, <NUM> of the frame <NUM>.

At least some of the apices <NUM> at the outflow end <NUM> of the frame <NUM> can have a respective aperture or opening <NUM> formed therein, as best shown in <FIG>. For example, in the illustrated embodiment, all of the apices <NUM> have an aperture <NUM> formed therein. In other embodiments, fewer than all of the apices <NUM> have apertures <NUM> formed therein. For example, one half, one third, or one fourth of the apices <NUM> can have apertures <NUM> formed therein. In such embodiments, the apices <NUM> having the apertures <NUM> can be uniformly distributed circumferentially around the outflow end <NUM> of the frame <NUM> (e.g., symmetrically-in an alternating type pattern).

The apertures <NUM> in the apices <NUM> can comprise various shapes. For example, the apertures <NUM> can be generally rectangular, circular, ovular, etc. The apertures <NUM> can be sized such that the apertures <NUM> can releasably be coupled to the delivery apparatus <NUM>, as further explained below (see, e.g., <FIG>).

The delivery apparatus <NUM> can comprise a handle (not shown), an outer catheter <NUM> and an implant delivery catheter <NUM>. The handle can be disposed adjacent to a proximal end portion of the delivery apparatus <NUM>. The outer catheter <NUM> and the implant delivery catheter <NUM> can extend coaxially from the proximal end of the delivery apparatus <NUM> toward an opposite, distal end portion <NUM> of the delivery apparatus <NUM>. The implant delivery catheter <NUM> can be disposed radially within and extend axially through a lumen <NUM> (<FIG>) of the outer catheter <NUM>.

Although the implant delivery catheter <NUM> is disposed radially within the outer catheter <NUM>, for purposes of illustration, the outer catheter <NUM> is shown as transparent (except in <FIG>) to better show the implant delivery catheter <NUM>.

The outer catheter <NUM> and the implant delivery catheter <NUM> can each be independently moveable relative to each other. In some embodiments, the delivery apparatus <NUM> can be configured such that relative axial movement between the outer and implant delivery catheters <NUM>, <NUM> at or near the proximal end of the delivery apparatus <NUM> can cause corresponding relative axial movement at or near the distal end <NUM> of the delivery apparatus <NUM>. For example, the delivery apparatus <NUM> can be configured such that axially advancing a proximal end of the implant delivery catheter <NUM> in the distal direction while maintaining the axial positioning of the outer catheter <NUM> causes a distal end of the implant delivery catheter <NUM> to axially advance in the distal direction relative to the outer catheter <NUM>.

In an alternative embodiment, the delivery apparatus <NUM> can be configured such that relative rotational movement between the outer and implant delivery catheters <NUM>, <NUM> at or near the proximal end of the delivery apparatus <NUM> can cause corresponding relative rotational movement at or near the distal end <NUM> of the delivery apparatus <NUM>. For example, the delivery apparatus <NUM> can be configured such that rotating the proximal end of the implant delivery catheter <NUM> in a first direction while preventing rotational movement of the outer catheter <NUM> causes the distal end of the implant delivery catheter <NUM> to rotate in the first direction relative to the outer catheter <NUM>.

The outer catheter <NUM> can have a shaft portion <NUM> having a distal end portion comprising a sheath portion <NUM>. The sheath <NUM> can be used to retain the prosthetic valve <NUM> in a radially compressed state, as best shown in <FIG>. The sheath <NUM> of the outer catheter <NUM> can comprise a tip portion <NUM> disposed at a distal end of the sheath <NUM>.

Referring now to <FIG>, the implant delivery catheter <NUM> can comprise a shaft <NUM> and a plurality of tines or arms <NUM>. The arms <NUM> of the implant delivery catheter <NUM> can extend axially from a distal end <NUM> of the shaft <NUM> and can be spaced apart circumferentially relative to each other. Although the illustrated embodiment shows eight arms, other embodiments can have less or more arms. For example, the implant delivery catheter <NUM> can have <NUM>-<NUM> arms, <NUM>-<NUM> arms, or <NUM>-<NUM> arms.

Referring now to <FIG>, the shaft <NUM> of the implant delivery catheter <NUM> can have a plurality of circumferentially extending slots <NUM> formed in one or more sides of the shaft <NUM>. Similar to the slots <NUM> of the release catheter <NUM>" of the delivery assembly <NUM>, the slots <NUM> can improve the flexibility of the implant delivery catheter <NUM> and can be configured to cause the implant delivery catheter to bend relatively more easily toward one side of the implant delivery catheter <NUM> than toward another side of the implant delivery catheter <NUM>.

The arms <NUM> of the implant delivery catheter <NUM> can each have a curved or hook portion <NUM> disposed at a distal end of a respective arm <NUM>. The hooks <NUM> can extend radially inward and can be used to releasably couple the prosthetic valve <NUM> to the delivery apparatus <NUM>. For example, referring now to <FIG>, the hooks <NUM> can be configured so that the hooks <NUM> extend radially through respective apertures <NUM> of the apices <NUM> of the prosthetic valve <NUM>, thereby releasably coupling the prosthetic valve <NUM> to the delivery apparatus <NUM> via the implant delivery catheter <NUM>, as further described below.

The arms <NUM> of the implant delivery catheter <NUM> can be configured to be radially expandable from a radially compressed state (e.g., <FIG>) to radially expanded state (e.g., <FIG>, <FIG>). This can be accomplished, for example, by forming the arms <NUM> from any of various suitable self-expanding materials (e.g., nickel titanium alloy ("NiTi"), such as Nitinol). The arms <NUM> can, for example, be formed by laser-cutting a Nitinol tube and shape-setting the arms <NUM> in the radially expanded state.

When constructed of a self-expandable material, the arms <NUM> of the implant delivery catheter <NUM> can be radially compressed by retracting the implant delivery catheter <NUM> relative to the outer catheter <NUM> or by advancing the outer catheter <NUM> relative to the implant delivery catheter <NUM> such that the arms <NUM> are disposed with the sheath <NUM> of the outer catheter <NUM>. The arms <NUM> can be radially expanded by advancing the implant delivery catheter <NUM> relative to the outer catheter <NUM> or by retracting the outer catheter <NUM> relative to the implant delivery catheter <NUM> such that the arms <NUM> are exposed from the sheath <NUM> of the outer catheter <NUM>.

As best shown in <FIG>, the arms <NUM> can be configured to have a release point <NUM>. At the release point <NUM>, the arms <NUM> can be radially tapered or angled relative to the distal end portions of the arms so as to allow the arms <NUM> to expand radially outward to the extent that the hooks <NUM> disengage from the apertures <NUM> of the prosthetic valve <NUM> when the release point <NUM> is exposed from the sheath <NUM> of the outer catheter <NUM>.

In some embodiments, each of the hooks <NUM> of the arms <NUM> can extend radially inwardly and can be angled at least slightly proximally. As such, the hooks <NUM> can be configured such that when the arms <NUM> expand from the radially compressed state to the radially expanded state the proximal angle of the hooks <NUM> increases relative to the apertures <NUM> of the frame <NUM>. Stated another way, the hooks <NUM> can be configured so as to engage the apices <NUM> of the frame <NUM> relatively more when the arms <NUM> are in the radially compressed state (to facilitate interlocking between the arms <NUM> and the frame <NUM>) than when the arms <NUM> are in the radially expanded state (to facilitate disengaging between the arms <NUM> and the frame <NUM>).

In this manner, the delivery apparatus <NUM> can be used to percutaneously deliver and position the prosthetic valve <NUM> in a native annulus of a heart. The prosthetic valve <NUM> can be releasably coupled to the delivery apparatus <NUM> by positioning the hooks <NUM> of the implant delivery catheter <NUM> into the apertures <NUM> in the frame <NUM> of the prosthetic valve <NUM>. The prosthetic valve <NUM> and the arms <NUM> of the implant delivery catheter <NUM> can be radially compressed or crimped and retained in their respective compressed configurations by positioning the prosthetic valve <NUM> and the arms <NUM> of the implant delivery catheter <NUM> within the sheath <NUM> of the outer catheter. The delivery apparatus <NUM> and thus the prosthetic valve <NUM> can then be inserted into a patient's body and advanced to a desired native annulus of the patient's heart (e.g., a native aortic annulus).

Once the delivery apparatus <NUM> and the prosthetic valve <NUM> are desirably positioned in the native annulus, the prosthetic valve <NUM> can be deployed by retracting the outer catheter <NUM> proximally relative to the implant delivery catheter <NUM> (or by advancing the implant delivery catheter <NUM> distally relative to the outer catheter <NUM>). As the prosthetic valve <NUM> is exposed from the sheath <NUM>, the prosthetic valve <NUM> begins radially expanding, as shown in <FIG>. Retracting the outer catheter <NUM> proximally farther allows the arms <NUM> of the implant delivery catheter <NUM> and thus the outflow end <NUM> of the prosthetic valve <NUM> to expand, as shown in <FIG>.

The prosthetic valve <NUM> can be positioned and/or repositioned, for example, by moving the implant delivery catheter <NUM>. The prosthetic valve <NUM> can also be partially and/or fully recompressed by retracting the implant delivery catheter <NUM> proximally relative to the outer catheter <NUM> (or by advancing the outer catheter <NUM> distally relative to the implant delivery catheter <NUM>), thus allowing the prosthetic valve <NUM> to be repositioned and redeployed and/or retrieved from the patient's body.

Once the prosthetic valve <NUM> is desirably positioned and secured with the native annulus, the sheath <NUM> can be retracted proximally relative to the implant delivery catheter <NUM> such that the release point <NUM> (<FIG>) of the arms <NUM> is exposed from the sheath <NUM>. This allows the arms <NUM> to fully expand radially outward to the extent that the hooks <NUM> retract from within the apertures <NUM> of the prosthetic valve <NUM>, thereby releasing the prosthetic valve <NUM> from the delivery apparatus <NUM>, as shown in <FIG>.

Referring now to <FIG>, in some embodiments, the delivery apparatus <NUM> can have an inner catheter <NUM> having an expansion element <NUM>. The inner catheter <NUM> can be disposed radially within and extend axially through a lumen <NUM> (<FIG>) of the implant delivery catheter <NUM> (which is an intermediate catheter in this embodiment) and can be independently moveable (e.g., axially slidable/translatable or rotatable) relative to the outer and implant delivery catheters <NUM>, <NUM>.

The expansion element <NUM> can be coupled to a distal end <NUM> of the inner catheter <NUM>. The expansion element <NUM> can have a generally frusto-conical shape. As such, the expansion element <NUM> can be used to assist and/or to cause radially expansion of the arms <NUM> of the implant delivery catheter <NUM>. For example, when the arms <NUM> of the implant delivery catheter <NUM> are exposed from the sheath <NUM> of the outer catheter <NUM>, the expansion element <NUM> can be retracted proximally relative to the implant delivery catheter <NUM> such that the expansion element <NUM> contacts the arms <NUM> and thus forces the arms <NUM> to expand radially outward.

The expansion element <NUM> can provide several significant advantages. For example, the expansion element <NUM> can be used to release the prosthetic valve <NUM> from the delivery apparatus <NUM> in the event that the self-expanding force of the arms <NUM> of implant delivery catheter <NUM> is insufficient to cause the arms <NUM> to radially expand enough to remove the hooks <NUM> from the apertures <NUM> of the prosthetic valve <NUM>. This can be particularly useful when, for example, a patient's native anatomy interferes with and thus prevents the arms <NUM> from fully expanding.

The expansion element <NUM> can also allow the arms <NUM> to be formed from suitable plastically-expandable materials (e.g., stainless steel, etc.) because the expansion element <NUM> can be used to expand the arms <NUM>.

In some embodiments, the expansion element <NUM> can be fixedly coupled to the inner catheter <NUM>. As such, relative axial motion between the expansion member <NUM> and the arms <NUM> of the implant delivery catheter <NUM> can be caused by pushing the inner catheter <NUM> distally or pulling the inner catheter proximally relative to the implant delivery catheter <NUM>, which in turn causes the expansion member <NUM> to respectively advance distally or retract proximally relative to the arms <NUM>.

In other embodiments, the expansion element <NUM> can be slidably coupled to the inner catheter <NUM>. For example, in some embodiments, rotating the inner catheter <NUM> relative to the expansion element <NUM> in a first direction causes the expansion element <NUM> to slide or translate proximally along the inner catheter <NUM> and into contact with the arms <NUM> of the implant delivery catheter <NUM>, and rotating the inner catheter <NUM> relative to the expansion element <NUM> in a second, opposite direction causes the expansion element <NUM> to slide or translate distally along the inner catheter <NUM> and away from the arms <NUM> of the implant delivery catheter <NUM>. This can be accomplished, for example, by forming the inner catheter <NUM> with external threads <NUM>, by forming the expansion element <NUM> with corresponding internal threads (not shown), and by preventing the expansion element <NUM> from rotating together with the inner catheter <NUM>, such as by slidably attaching or connecting the expansion element <NUM> to another component of the delivery apparatus (e.g., the outer catheter <NUM>, the shaft <NUM>, and/or the arms <NUM>) by a shaft or sleeve <NUM>. In other embodiments, the outer surface of the expansion element <NUM> can, for example, be formed with longitudinal slots (not shown) that receive the arms <NUM>. As such, the arms <NUM> are allowed to slide axially relative to the slots, but the slots prevent rotation of the expansion element <NUM> when the inner shaft <NUM> is rotated.

Claim 1:
A prosthetic implant delivery assembly (<NUM>), comprising:
a prosthetic implant (<NUM>) comprising an expandable stent portion (<NUM>) having a plurality of apices (<NUM>) circumferentially spaced around a first end portion (<NUM>) of the stent (<NUM>), wherein at least some of the apices (<NUM>) comprise an aperture (<NUM>); and
an elongate catheter (<NUM>) comprising a plurality of radially expandable arms (<NUM>) extending axially from a distal end (<NUM>) of a shaft (<NUM>) of the catheter (<NUM>), each arm (<NUM>) having a hook portion (<NUM>) which extends radially inwardly,
wherein the hook portions (<NUM>) of the arms (<NUM>) releasably engage a respective aperture (<NUM>) of the stent (<NUM>), and the arms (<NUM>) of the catheter (<NUM>) are configured such that the arms (<NUM>) can expand radially relative to the catheter (<NUM>) when the arms (<NUM>) are exposed from within a sheath (<NUM>) such that the hook portions (<NUM>) disengage the apertures (<NUM>) of the stent (<NUM>).