Patent Description:
Prosthetic cardiac valves have been used for many years to treat cardiac valvular disorders. The native heart valves (such as the aortic, pulmonary and mitral valves) serve critical functions in assuring the forward flow of an adequate supply of blood through the cardiovascular system. These heart valves can be rendered less effective by congenital, inflammatory or infectious conditions. Such damage to the valves can result in serious cardiovascular compromise or death. For many years the definitive treatment for such disorders was the surgical repair or replacement of the valve during open heart surgery, but such surgeries are prone to many complications. More recently a transvascular technique has been developed for introducing and implanting a prosthetic heart valve using a flexible catheter in a manner that is less invasive than open heart surgery.

In this technique, a prosthetic valve is mounted in a crimped state on the end portion of a flexible catheter and advanced through a blood vessel of the patient until the prosthetic valve reaches the implantation site. The prosthetic valve at the catheter tip is then expanded to its functional size at the site of the defective native valve such as by inflating a balloon on which the prosthetic valve is mounted. Alternatively, the prosthetic valve can have a resilient, self-expanding stent or frame that expands the prosthetic valve to its functional size when it is advanced from a delivery sheath at the distal end of the catheter.

A prosthetic valve that has a relatively large profile or diameter in the compressed state can inhibit the physician's ability to advance the prosthetic valve through the femoral artery or vein. More particularly, a smaller profile allows for treatment of a wider population of patients, with enhanced safety. Thus, a need exists for delivery devices that can minimize the overall crimp profile of the prosthetic valve for the delivery of the prosthetic valve through the patient's vasculature.

Relatively long delivery devices, such as used for transfemoral delivery of a prosthetic valve, can inhibit the physician's ability to position the prosthetic valve precisely at the desired implantation site because the forces applied to the handle at one end of the delivery device can cause unwanted movement of the prosthetic valve at the opposite end of the delivery device. Thus, a need exists for delivery devices that allow a physician to accurately control the positioning of the prosthetic valve at the desired implantation location.

<CIT> discloses a stent delivery system which comprises an inner member and an expandable balloon mounted in a collapsed state on the inner member. The expandable balloon has a first and a second end. A compressible stent having a first diameter is mounted in a compressed state around the expandable balloon between the first and second ends of the balloon. At least a first retainer pillow is formed in the expandable balloon at its first end and has an outer diameter which is at least substantially equal to the diameter of the compressed stent. A first pillow support member is mounted on the inner member and supports the first retainer pillow to maintain the pillow's outer diameter.

<CIT> relates to a catheter structure for dilating and for positioning stents, comprising a catheter having an inflatable balloon, and wherein two collars are fixed around the said catheter inside the balloon and intended to define two annular shoulders one in front of the other and spaced apart in parallel. A tubular adapter is arranged around the said catheter portion between the said collars, and the said balloon, when empty, is wrapped around the collars with the said tubular adapter comprised between same.

<CIT> relates to retainer structures which maintain stented valves on the balloon of a balloon catheter during delivery of the valve to an implantation node and subsequent expansion of the valve. The retainer structures define a raised edge relative to the outer surface of the balloon and limit movement of the valve longitudinally relative to the balloon. Deflation of the balloon following expansion of the valve stent releases the valve.

When introducing a delivery device into the body, an introducer sheath typically is inserted first and then the delivery device is inserted through the introducer sheath and into the body. If the prosthetic valve is mounted on a balloon catheter, the prosthetic valve can contact the inner surface of the introducer sheath and may become dislodged from its preferred location on the balloon catheter, depending on the size of the crimped valve. Thus, a need exists for delivery devices that can better retain the crimped valve at its desired location on the balloon catheter as it is advanced through an introducer sheath.

The invention is a delivery device for implantation of a prosthetic heart valve as defined in claim <NUM> and a system for delivering a prosthetic heart valve as defined in claim <NUM> and a system for delivering a prosthetic heart valve as defined in claim <NUM>. Described herein are systems and methods for delivering prosthetic devices, such as prosthetic heart valves, through the body and into the heart for implantation therein. The prosthetic devices delivered with the delivery systems disclosed herein are, for example, radially expandable from a radially compressed state mounted on the delivery system to a radially expanded state for implantation using an inflatable balloon (or equivalent expansion device) of the delivery system. Exemplary delivery routes through the body and into the heart include transfemoral routes, transapical routes, and transaortic routes, among others. Although the devices and methods disclosed herein are particular suited for implanting prosthetic heart valves (e.g., a prosthetic aortic valve or prosthetic mitral valve), the disclosed devices and methods can be adapted for implanting other types of prosthetic valves within the body (e.g., prosthetic venous valves) or other types of expandable prosthetic devices adapted to be implanted in various body lumens.

A preferred embodiment is defined by independent claim <NUM> and further specified by the dependent claims.

An exemplary delivery device for implantation of a prosthetic device (e.g., a prosthetic heart valve) within the heart, such as via a transapical or transaortic route, as defined in claim <NUM> comprises, inter alia, an inflatable balloon, a proximal stop, and a distal stop. The stops are configured to limit longitudinal movement of the prosthetic device relative to the balloon while the prosthetic device is mounted over the balloon in the radially compressed state between the proximal stop and the distal stop. The proximal stop and the distal stop each comprise an end portion positioned within the balloon and configured to be positioned adjacent the prosthetic device when the prosthetic device is radially compressed between the proximal and distal stops. Each of the stop end portions can comprise at least one longitudinally extending slot that allows the respective stop end portion to be radially compressed to a smaller diameter. The at least one longitudinally extending slot in each stop end portion can also be configured to allow a balloon-inflation fluid to flow radially through the respective stop and into the region of the balloon extending through the prosthetic valve.

In some embodiments, when a prosthetic device is mounted on the delivery device in the radially compressed state, the proximal stop and the distal stop are configured to allow a balloon-inflation fluid to flow from a proximal portion of the balloon, through the at least one slot in the proximal stop, through an intermediate portion of the balloon positioned within the prosthetic device, through the at least one slot in the distal stop, and into a distal portion of the balloon.

In some embodiments, a proximal end of the balloon is attached to the proximal stop and a distal end of the balloon is attached to the distal stop.

In some embodiments, the delivery device further comprises an outer shaft having a lumen and an inner shaft extending through the lumen of the outer shaft, with the proximal stop attached to a distal end of the outer shaft and positioned around the inner shaft and the distal stop attached to an outer surface of the inner shaft.

In some embodiments, the proximal stop further comprises a proximal portion attached to the distal end of the outer shaft and to a proximal end of the balloon, and an intermediate portion extending between the proximal portion and the end portion, the intermediate portion having an outer diameter that is less than an outer diameter of the proximal portion and less than the diameter of the end portion.

In some embodiments, the proximal stop is attached to the distal end of the outer shaft and further comprises at least one fluid passageway that allows an inflation fluid to flow through the at least one passageway and into the balloon.

In some embodiments, the distal stop further comprises a distal portion attached to a distal end of the balloon and an intermediate portion extending between the distal portion and the end portion, the intermediate portion having an outer diameter that is less than an outer diameter of the distal portion and less than the diameter of the end portion.

In some embodiments, the end portion of each stop decreases in diameter in a direction extending away from the prosthetic device.

In some embodiments, the delivery device further comprises a nosecone attached to a distal end of the distal stop.

In some embodiments, at least one of the stop end portions comprises at least three longitudinal slots that allow the stop end portion to be radially compressed to a smaller diameter when the prosthetic device is crimped onto the delivery device.

An exemplary method of implanting a prosthetic heart valve within the heart not claimed by the claims comprises: (a) introducing a distal end portion of a delivery device into the native aortic valve of the heart, a distal end portion of the delivery device comprising an inflatable balloon, a proximal stop and a distal stop positioned at least partially within the balloon, and a radially expandable prosthetic heart valve mounted over the balloon and between the proximal stop and the distal stop in a radially compressed state; (b) inflating the balloon to radially expand the prosthetic heart valve within the native aortic valve, wherein the balloon is inflated with an inflation fluid that flows radially through the proximal and distal stops; (c) deflating the balloon; and (d) retracting the delivery device from the heart.

In some embodiments, the proximal stop is positioned adjacent to a proximal end of the prosthetic heart valve and the distal stop is positioned adjacent to a distal end of the prosthetic heart valve, such that the prosthetic device is longitudinally contained between the proximal and distal stops during introduction of the prosthetic heart valve through an introducer sheath into the body.

In some embodiments not claimed by the claims, inflating the balloon comprises causing the inflation fluid to flow: (i) through a first passageway in the proximal stop and into a proximal portion of the balloon; (ii) from the proximal portion of the balloon, through a second passageway in the proximal stop, and into an intermediate portion of the balloon within the prosthetic device; and (iii) from the intermediate portion of the balloon, through a passageway in the distal stop, and into a distal portion of the balloon.

In some embodiments not claimed by the claims, prior to introducing the delivery device into the heart, the prosthetic heart valve is crimped to the radially compressed state onto delivery device while the proximal stop and the distal stop are simultaneously radially compressed. The prosthetic heart valve can have a first outer diameter in the radially compressed state and the proximal stop and distal stop can be compressed from a second outer diameter to about the first outer diameter during the crimping. When compressive pressure is released after the crimping, the proximal stop and distal stop can be configured to resiliently expand from about the first outer diameter to about the second outer diameter.

An exemplary system for delivering a prosthetic device into a patient as defined in claim <NUM>, comprises an introducer sheath configured to be inserted partially into a patient, a loader configured to be inserted into a proximal end the introducer sheath, and a delivery device configured to be passed through the loader and the introducer sheath into the patient carrying a prosthetic device to be implanted in the patient. The loader comprises a flush port for selectively introducing fluid into the loader and a bleed port for selectively releasing fluid from within the loader, and both the flush port and the bleed port are sealed with the same resiliently flexible annular sealing member. The sealing member can comprise a push tab that extends radially through the bleed port, such that the bleed port is configured to be selectively opened by depressing the push tab in the radially inward direction.

A delivery apparatus for implanting a prosthetic, transcatheter heart valve via a patient's vasculature can include an adjustment device for adjusting the position of a balloon relative to a crimped prosthetic valve (and/or vice versa). A balloon catheter can extend coaxially with a guide (or flex) catheter, and a balloon member at the distal end of the balloon catheter can be positioned proximal or distal to a crimped prosthetic valve. As described below in more detail, the balloon member and the crimped prosthetic valve can enter the vasculature of a patient through an introducer sheath and, once the balloon member and the crimped prosthetic valve reach a suitable location in the body, the relative position of the prosthetic valve and balloon member can be adjusted so that the balloon member is positioned within the frame of the prosthetic valve so that the prosthetic valve eventually can be expanded at the treatment site. Once the crimped prosthetic valve is positioned on the balloon, the prosthetic valve is advanced to the vicinity of the deployment location (i.e., the native aortic valve) and the adjustment device can further be used to accurately adjust or "fine tune" the position of the prosthetic valve relative to the desired deployment location.

<FIG> shows a delivery apparatus <NUM> adapted to deliver a prosthetic heart valve <NUM> (shown schematically in <FIG>) (e.g., a prosthetic aortic valve) to a heart. The apparatus <NUM> generally includes a steerable guide catheter <NUM> (<FIG>), and a balloon catheter <NUM> extending through the guide catheter <NUM>. The guide catheter can also be referred to as a flex catheter or a main catheter. The use of the term main catheter should be understood, however, to include flex or guide catheters, as well as other catheters that do not have the ability to flex or guide through a patient's vasculature.

The guide catheter <NUM> and the balloon catheter <NUM> in the illustrated embodiment are adapted to slide longitudinally relative to each other to facilitate delivery and positioning of prosthetic valve <NUM> at an implantation site in a patient's body, as described in detail below.

The guide catheter <NUM> includes a handle portion <NUM> and an elongated guide tube, or shaft, <NUM> extending from handle portion <NUM> (<FIG>). <FIG> shows the delivery apparatus without the guide catheter shaft <NUM> for purposes of illustration. <FIG> shows the guide catheter shaft <NUM> extending from the handle portion <NUM> over the balloon catheter. The balloon catheter <NUM> includes a proximal portion <NUM> (<FIG>) adjacent handle portion <NUM> and an elongated shaft <NUM> that extends from the proximal portion <NUM> and through handle portion <NUM> and guide tube <NUM>. The handle portion <NUM> can include a side arm <NUM> having an internal passage which fluidly communicates with a lumen defined by the handle portion <NUM>.

An inflatable balloon <NUM> is mounted at the distal end of balloon catheter <NUM>. As shown in <FIG>, the delivery apparatus <NUM> is configured to mount the prosthetic valve <NUM> in a crimped state proximal to the balloon <NUM> for insertion of the delivery apparatus and prosthetic valve into a patient's vasculature, which is described in detail in <CIT> (U. Application No. <CIT>). Because prosthetic valve <NUM> is crimped at a location different from the location of balloon <NUM> (e.g., in this case prosthetic valve <NUM> desirably is crimped proximal to balloon <NUM>), prosthetic valve <NUM> can be crimped to a lower profile than would be possible if prosthetic valve <NUM> was crimped on top of balloon <NUM>. This lower profile permits the surgeon to more easily navigate the delivery apparatus (including crimped valve <NUM>) through a patient's vasculature to the treatment location. The lower profile of the crimped prosthetic valve is particularly helpful when navigating through portions of the patient's vasculature which are particularly narrow, such as the iliac artery. The lower profile also allows for treatment of a wider population of patients, with enhanced safety.

A nose piece <NUM> (<FIG>) can be mounted at the distal end of the delivery apparatus <NUM> to facilitate advancement of the delivery apparatus <NUM> through the patient's vasculature to the implantation site. In some instances, it may be useful to have nose piece <NUM> connected to a separate elongated shaft so that nose piece <NUM> can move independently of other elements of delivery apparatus <NUM>. Nose piece <NUM> can be formed of a variety of materials, including various plastic materials.

As can be seen in <FIG>, the balloon catheter <NUM> in the illustrated configuration further includes an inner shaft <NUM> (<FIG>) that extends from proximal portion <NUM> and coaxially through the outer balloon catheter shaft <NUM> and the balloon <NUM>. The balloon <NUM> can be supported on a distal end portion of inner shaft <NUM> that extends outwardly from the outer shaft <NUM> with a proximal end portion <NUM> of the balloon secured to the distal end of outer shaft <NUM> (e.g., with a suitable adhesive) (<FIG>). The outer diameter of inner shaft <NUM> is sized such that an annular space is defined between the inner and outer shafts along the entire length of the outer shaft. The proximal portion <NUM> of the balloon catheter can be formed with a fluid passageway (not shown) that is fluidly connectable to a fluid source (e.g., saline) for inflating the balloon. The fluid passageway is in fluid communication with the annular space between inner shaft <NUM> and outer shaft <NUM> such that fluid from the fluid source can flow through fluid passageway, through the space between the shafts, and into balloon <NUM> to inflate the same and deploy prosthetic valve <NUM>.

The proximal portion <NUM> also defines an inner lumen that is in communication with a lumen <NUM> of the inner shaft <NUM> that is sized to receive guide wire (not shown) that can extend coaxially through the inner shaft <NUM> and the nose cone <NUM>.

The inner shaft <NUM> and outer shaft <NUM> of the balloon catheter can be formed from any of various suitable materials, such as nylon, braided stainless steel wires, or a polyether block amide (commercially available as Pebax®). The shafts <NUM>, <NUM> can have longitudinal sections formed from different materials in order to vary the flexibility of the shafts along their lengths. The inner shaft <NUM> can have an inner liner or layer formed of Teflon® to minimize sliding friction with a guide wire.

The distal end portion of the guide catheter shaft <NUM> comprises a steerable section <NUM> (<FIG>), the curvature of which can be adjusted by the operator to assist in guiding the apparatus through the patient's vasculature, and in particular, the aortic arch. The handle <NUM> in the illustrated embodiment comprises a distal handle portion <NUM> and a proximal handle portion <NUM>. The distal handle portion <NUM> functions as a mechanism for adjusting the curvature of the distal end portion of the guide catheter shaft <NUM> and as a flex indicating device that allows a user to measure the relative amount of flex of the distal end of the guide catheter shaft <NUM>. In addition, the flex indicating device provides a visual and tactile response at the handle the device, which provides a surgeon with an immediate and direct way to determine the amount of flex of the distal end of the catheter.

The distal handle portion <NUM> can be operatively connected to the steerable section <NUM> and functions as an adjustment mechanism to permit operator adjustment of the curvature of the steerable section via manual adjustment of the handle portion. Explaining further, the handle portion <NUM> comprises a flex activating member <NUM>, an indicator pin <NUM>, and a cylindrical main body, or housing <NUM>. As shown in <FIG> and <FIG>, the flex activating member <NUM> comprises an adjustment knob <NUM> and a shaft <NUM> extending proximally from the knob into the housing <NUM>. A proximal end portion of the guide catheter shaft <NUM> extends into and is fixed within the central lumen of the housing <NUM>. An inner sleeve <NUM> surrounds a portion of the guide catheter shaft <NUM> inside the housing <NUM>. A threaded slide nut <NUM> is disposed on and is slidable relative to the sleeve <NUM>. The slide nut <NUM> is formed with external threads that mate with internal threads <NUM> of the shaft <NUM>.

The slide nut <NUM> can be formed with two slots formed on the inner surface of the nut and extending the length thereof. The sleeve <NUM> can be formed with longitudinally extending slots that are aligned with the slots of the slide nut <NUM> when the slide nut is placed on the sleeve. Disposed in each slot is a respective elongated nut guide, which can be in the form of an elongated rod or pin <NUM>. The nut guides <NUM> extend radially into respective slots in the slide nut <NUM> to prevent rotation of the slide nut <NUM> relative to the sleeve <NUM>. By virtue of this arrangement, rotation of the adjustment knob <NUM> (either clockwise or counterclockwise) causes the slide nut <NUM> to move longitudinally relative to the sleeve <NUM> in the directions indicated by double-headed arrow <NUM>.

One or more pull wires <NUM> (<FIG>) couple the adjustment knob <NUM> to the steerable section <NUM> to adjust the curvature of the steerable section upon rotation of the adjustment knob. For example, the proximal end portion of the pull wire <NUM> can extend into and can be secured to a retaining pin, such as by crimping the pin around the proximal end of the pull wire, which pin is disposed in a slot in the slide nut <NUM>. The pull wire extends from the pin, through the slot in the slide nut, a slot in the sleeve <NUM>, and into and through a pull wire lumen in the shaft <NUM>. The distal end portion of the pull wire is secured to the distal end portion of the steerable section <NUM>.

The pin, which retains the proximal end of the pull wire <NUM>, is captured in the slot in the slide nut <NUM>. Hence, when the adjustment knob <NUM> is rotated to move the slide nut <NUM> in the proximal direction, the pull wire also is moved in the proximal direction. The pull wire pulls the distal end of the steerable section <NUM> back toward the handle portion, thereby bending the steerable section and reducing its radius of curvature. The friction between the adjustment knob <NUM> and the slide nut <NUM> is sufficient to hold the pull wire taut, thus preserving the shape of the bend in the steerable section if the operator releases the adjustment knob <NUM>. When the adjustment knob <NUM> is rotated in the opposite direction to move the slide nut <NUM> in the distal direction, tension in the pull wire is released. The resiliency of the steerable section <NUM> causes the steerable to return its normal, non-deflected shape as tension on the pull wire is decreased. Because the pull wire is not fixedly secured to the slide nut <NUM> (the pin can move within the slot in the nut), movement of the slide nut in the distal direction does not push on the end of the pull wire, causing it to buckle. Instead, the pin is allowed to float within the slot of the slide nut <NUM> when the knob <NUM> is adjusted to reduce tension in the pull wire, preventing buckling of the pull wire.

In particular embodiments, the steerable section <NUM> in its non-deflected shape is slightly curved and in its fully curved position, the steerable section generally conforms to the shape of the aortic arch. In other embodiments, the steerable section can be substantially straight in its non-deflected position.

The distal handle portion <NUM> can have other configurations that are adapted to adjust the curvature of the steerable section <NUM>. One such alternative handle configuration is shown in co- pending <CIT> (published under Publication No. <CIT>). Additional details relating to the steerable section and handle configuration discussed above can be found in <CIT> (published as U. Publication No. <CIT>).

The shaft <NUM> also includes an externally threaded surface portion <NUM>. As shown in <FIG>, a base portion <NUM> of the indicator pin <NUM> mates with the externally threaded surface portion <NUM> of the shaft <NUM>. The shaft <NUM> extends into the main body <NUM> and the indicator pin <NUM> is trapped between the externally threaded surface portion <NUM> and the main body <NUM>, with a portion of the indicator pin <NUM> extending into a longitudinal slot <NUM> of the handle. As the knob <NUM> rotated to increase the curvature of the distal end of the guide catheter shaft <NUM>, the indicator pin <NUM> tracks the external threaded portion <NUM> of the flex activating member and moves in the proximal direction inside of the slot <NUM>. The greater the amount of rotation of the knob <NUM>, the further indicator pin <NUM> moves towards the proximal end of the proximal handle portion <NUM>. Conversely, rotating the knob <NUM> in the opposite direction decreases the curvature of the distal end of the guide catheter shaft <NUM> (i.e., straightens the guide catheter shaft) and causes corresponding movement of the indicator pin <NUM> toward the distal end of the distal handle portion <NUM>.

The outer surface of the main body <NUM> of the distal handle portion <NUM> can include visual indicia adjacent the slot <NUM> that indicate the amount of flex of the distal end of the guide catheter shaft <NUM>, based on the position of the indicator pin <NUM> relative to the visual indicia. Such indicia can identify the amount of flex in any of a variety of manners. For example, the outer surface of the main body <NUM> can include a series of numbers (e.g., <NUM> to <NUM>) adjacent the slot that indicate the amount of curvature of the guide catheter shaft <NUM> based on the position of the indicator pin <NUM> relative to the number scale.

As described above, when the delivery apparatus is introduced into the vasculature of the patient, a crimped prosthetic valve <NUM> is positioned proximal to the balloon <NUM> (<FIG>). Prior to expansion of the balloon <NUM> and deployment of prosthetic valve <NUM> at the treatment site, the prosthetic valve <NUM> is moved relative to the balloon (or vice versa) to position the crimped prosthetic valve on the balloon for deploying (expanding) the prosthetic valve. As discussed below, the proximal handle portion <NUM> serves as an adjustment device that can be used to move the balloon <NUM> proximally into position within the frame of prosthetic valve <NUM>, and further to accurately position the balloon and the prosthetic valve at the desired deployment location.

As shown in <FIG> and <FIG>, the proximal handle portion <NUM> comprises an outer housing <NUM> and an adjustment mechanism <NUM>. The adjustment mechanism <NUM>, which is configured to adjust the axial position of the balloon catheter shaft <NUM> relative to the guide catheter shaft <NUM>, comprises an adjustment knob <NUM> and a shaft <NUM> extending distally into the housing <NUM>. Mounted within the housing <NUM> on the balloon catheter shaft <NUM> is an inner support <NUM>, which in turn mounts an inner shaft <NUM> (also referred to as a slider or sliding mechanism) (also shown in <FIG>). The inner shaft <NUM> has a distal end portion <NUM> formed with external threads that mate with internal threads <NUM> that extend along the inner surface of the adjustment mechanism <NUM>. The inner shaft <NUM> further includes a proximal end portion <NUM> that mounts a securement mechanism <NUM>, which is configured to retain the position of the balloon catheter shaft <NUM> relative to the proximal handle portion <NUM> for use of the adjustment mechanism <NUM>, as further described below. The inner shaft <NUM> can be coupled to the inner support <NUM> such that rotation of shaft <NUM> causes the inner shaft <NUM> to move axially within the handle. For example, the inner support <NUM> can have an axially extending rod or rail that extends into slot formed in the inner surface of the inner shaft <NUM>. The rod or rail prevents rotation of the inner shaft <NUM> but allows it to move axially upon rotation of the shaft <NUM>.

The securement mechanism <NUM> includes internal threads that mate with external threads of the proximal end portion <NUM> of the inner shaft. Mounted within the proximal end portion <NUM> on the balloon catheter shaft <NUM> is a pusher element <NUM> and a shaft engagement member in the form of a collet <NUM>. The collet <NUM> is configured to be manipulated by the securement mechanism between a first state in which collet allows the balloon catheter shaft to be moved freely in the longitudinal and rotational directions and a second state in which the collet frictionally engages the balloon catheter shaft and prevents rotational and longitudinal movement of the balloon catheter shaft relative to the inner shaft <NUM>, as further described below.

As best shown in <FIG>, the collet <NUM> comprises a distal end portion <NUM>, an enlarged proximal end portion <NUM>, and a lumen <NUM> that receives the balloon catheter shaft <NUM>. A plurality of axially extending, circumferentially spaced slots <NUM> extend from the proximal end of the collet to a location on the distal end portion <NUM>, thereby forming a plurality of flexible fingers <NUM>. The proximal end portion can be formed with a tapered end surface <NUM> that engages a corresponding tapered end surface of the pusher element <NUM> (<FIG>).

As noted above, the securement mechanism <NUM> is operable to restrain movement of the balloon catheter shaft <NUM> (in the axial and rotational directions) relative to the proximal handle portion <NUM>. Explaining further, the securement mechanism <NUM> is movable between a proximal position (shown in <FIG> and <FIG>) and a distal position closer to the adjacent end of the knob <NUM>. In the proximal position, the collet <NUM> applies little, if any, force against the balloon catheter shaft <NUM>, which can slide freely relative to the collet <NUM>, the entire handle <NUM>, and the guide catheter shaft <NUM>. When the securement mechanism <NUM> is rotated so as to move to its distal position closer to knob <NUM>, the securement mechanism urges pusher element <NUM> against the proximal end of the collet <NUM>. The tapered surface of the pusher element pushes against the corresponding tapered surface <NUM> of the collet, forcing fingers <NUM> radially inward against the outer surface of the balloon catheter shaft <NUM>. The holding force of the collet <NUM> against the balloon catheter shaft locks the balloon catheter shaft relative to the inner shaft <NUM>. In the locked position, rotation of the adjustment knob <NUM> causes the inner shaft <NUM> and the balloon catheter shaft <NUM> to move axially relative to the guide catheter shaft <NUM> (either in the proximal or distal direction, depending on the direction the knob <NUM> is rotated).

The adjustment knob <NUM> can be utilized to position the prosthetic valve <NUM> on the balloon <NUM> and/or once the prosthetic valve <NUM> is on the balloon, to position the prosthetic valve and the balloon at the desired deployment site within the native valve annulus. One specific method for implanting the prosthetic valve <NUM> in the native aortic valve is as follows. The prosthetic valve <NUM> initially can be crimped on a mounting region <NUM> (<FIG> and <FIG>) of the balloon catheter shaft <NUM> immediately adjacent the proximal end of the balloon <NUM> or slightly overlapping the proximal end of the balloon. The proximal end of the prosthetic valve can abut the distal end <NUM> of the guide catheter shaft <NUM> (<FIG>), which keeps the prosthetic valve in place on the balloon catheter shaft as the delivery apparatus and prosthetic valve are inserted through an introducer sheath. The prosthetic valve <NUM> can be delivered in a transfemoral procedure by first inserting an introducer sheath into the femoral artery and pushing the delivery apparatus through the introducer sheath into the patient's vasculature.

After the prosthetic valve <NUM> is advanced through the narrowest portions of the patient's vasculature (e.g., the iliac artery), the prosthetic valve <NUM> can be moved onto the balloon <NUM>. For example, a convenient location for moving the prosthetic valve onto the balloon is the descending aorta. The prosthetic valve can be moved onto the balloon, for example, by holding the handle portion <NUM> steady (which retains the guide catheter shaft <NUM> in place), and moving the balloon catheter shaft <NUM> in the proximal direction relative to the guide catheter shaft <NUM>. As the balloon catheter shaft is moved in the proximal direction, the distal end <NUM> of the guide catheter shaft pushes against the prosthetic valve, allowing the balloon <NUM> to be moved proximally through the prosthetic valve in order to center the prosthetic valve on the balloon, as depicted in <FIG>. The balloon catheter shaft can include one or more radiopaque markers to assist the user in positioning the prosthetic valve at the desired location on the balloon. The balloon catheter shaft <NUM> can be moved in the proximal direction by simply sliding/pulling the balloon catheter shaft in the proximal direction if the securement mechanism <NUM> is not engaged to retain the shaft <NUM>. For more precise control of the shaft <NUM>, the securement mechanism <NUM> can be engaged to retain the shaft <NUM>, in which case the adjustment knob <NUM> is rotated to effect movement of the shaft <NUM> and the balloon <NUM>.

As shown in <FIG>, the delivery apparatus can further include a mounting member <NUM> secured to the outer surface of the shaft <NUM> within the balloon <NUM>. The mounting member helps retain the prosthetic valve in place on the balloon by facilitating the frictional engagement between the prosthetic valve and the outer surface of the balloon. The mounting member <NUM> helps retain the prosthetic valve in place for final positioning of the prosthetic valve at the deployment location, especially when crossing the native leaflets, which typically are calcified and provide resistance against movement of the prosthetic valve. The nose cone <NUM> can include a proximal portion <NUM> inside the balloon to assist in positioning the prosthetic valve. The proximal portion <NUM> desirably comprises a tapered member that has a maximum diameter at its proximal end adjacent the distal end of the prosthetic valve (<FIG>) and tapers in a direction toward the distal end of the nosecone <NUM>. The tapered member <NUM> serves as a transition section between the nosecone and the prosthetic valve as the prosthetic valve is pushed through the calcified native leaflets by shielding the distal end of the prosthetic valve from contacting the native leaflets. Although <FIG> shows the prosthetic valve having a crimped diameter slightly larger than the diameter of the tapered member <NUM> at its proximal end, the tapered member <NUM> can have a diameter at its proximal end that is the same as or slightly larger than the diameter of the crimped prosthetic valve, or at least the same as or slightly larger than the diameter of the metal frame of the crimped prosthetic valve.

As shown in <FIG>, the prosthetic valve desirably is positioned on the balloon for deployment such that the distal end of the prosthetic valve is slightly spaced from the nose cone portion <NUM>. When the prosthetic valve is positioned as shown in <FIG>, the guide catheter shaft <NUM> can be moved proximally relative to the balloon catheter shaft <NUM> so that the guide catheter shaft is not covering the inflatable portion of the balloon <NUM>, and therefore will not interfere with inflation of the balloon.

As the prosthetic valve <NUM> is guided through the aortic arch and into the ascending aorta, the curvature of the steerable section <NUM> can be adjusted (as explained in detail above) to help guide or steer the prosthetic valve through that portion of the vasculature. As the prosthetic valve is moved closer toward the deployment location within the aortic annulus, it becomes increasingly more difficult to control the precise location of the prosthetic valve by pushing or pulling the handle portion <NUM> due to the curved section of the delivery apparatus. When pushing or pulling the handle portion <NUM>, slack is removed from the curved section of the delivery apparatus before the pushing/pulling force is transferred to the distal end of the delivery apparatus. Consequently, the prosthetic valve tends to "jump" or move abruptly, making precise positioning of the prosthetic valve difficult.

For more accurate positioning of the prosthetic valve within the aortic annulus, the prosthetic valve <NUM> is placed as close as possible to its final deployment location (e.g., within the aortic annulus such that an inflow end portion of the prosthetic valve is in the left ventricle and an outflow end portion of the prosthetic valve is in the aorta) by pushing/pulling the handle <NUM>, and final positioning of the prosthetic valve is accomplished using the adjustment knob <NUM>. To use the adjustment knob <NUM>, the securement mechanism <NUM> is placed in its locked position, as described above. Then, the handle <NUM> is held steady (which retains the guide catheter shaft <NUM> in place) while rotating the adjustment knob <NUM> to move the balloon catheter shaft <NUM>, and thus the prosthetic valve, in the distal or proximal directions. For example, rotating the knob in a first direction (e.g., clockwise), moves the prosthetic valve proximally into the aorta, while rotating the knob in a second, opposite direction (e.g., counterclockwise) advances the prosthetic valve distally toward the left ventricle. Advantageously, operation of the adjustment knob <NUM> is effective to move the prosthetic valve in a precise and controlled manner without sudden, abrupt movements as can happen when pushing or pulling the delivery apparatus for final positioning.

When the prosthetic valve is at the deployment location, the balloon <NUM> is inflated to expand the prosthetic valve <NUM> (as depicted in <FIG>) so as to contact the native annulus. The expanded prosthetic valve becomes anchored within the native aortic annulus by the radial outward force of the valve's frame against the surrounding tissue.

The mounting member <NUM> within the balloon is configured to allow the inflation fluid (e.g., saline) to flow unobstructed from the proximal end of the balloon to the distal end of the balloon. As best shown in <FIG>, for example, the mounting member <NUM> comprises a coiled wire (e.g., a metal coil) having a first section 124a, a second section 124b, a third section 124c, a fourth section 124d, and a fifth section 124e. When the prosthetic valve <NUM> is positioned on the balloon for deployment, the second section 124b is immediately adjacent the proximal end of the prosthetic valve and the fourth section 124d is immediately adjacent the distal end of the prosthetic valve. The first and fifth sections 124a, 124e, respectively, which are at the proximal and distal ends of the mounting member, respectively, are secured to the balloon catheter shaft. The second, third, and fourth sections 124b, 124c, and 124d, respectively, are relatively larger in diameter than the first and fifth sections and are spaced radially from the outer surface of the balloon catheter shaft. As can be seen, the second section 124b and the fourth section 124d are formed with spaces between adjacent coils. The third section can be formed with smaller spaces (or no spaces) between adjacent coils to maximize the surface area available to retain the prosthetic valve on the balloon during final positioning of the prosthetic valve at the deployment location.

Referring to <FIG>, the spacing between coils of the second and fourth sections 124b, 124d allows the inflation fluid to flow radially inwardly through the coils of the second section 124b, axially through the lumen of the third section 124c, radially outwardly through the coils of the fourth section 124d, into the distal section of the balloon, in the direction of arrows <NUM>. The nose cone portion <NUM> also can be formed with one or more slots <NUM> that allow the inflation fluid to flow more easily past the proximal nose cone portion <NUM> into the distal section of the balloon. In the illustrated embodiment, the proximal nose cone portion <NUM> has three circumferentially spaced slots <NUM>. Since the inflation fluid can pressurize and inflate the proximal and distal sections of the balloon at substantially the same rate, the balloon can be inflated more evenly for controlled, even expansion of the prosthetic valve.

<FIG> illustrate a mounting member <NUM> according to another embodiment. The mounting member <NUM> comprises a cylindrical inner wall <NUM>, a cylindrical outer wall <NUM>, and a plurality of angularly spaced ribs <NUM> separating the inner and outer walls. The inner wall <NUM> is secured to the outer surface of the shaft <NUM> within the balloon. In particular embodiments, the mounting member <NUM> can be made of a relatively rigid material (e.g., polyurethane or another suitable plastic) that does not radially compress when the prosthetic valve is moved onto the balloon. As shown in <FIG>, during inflation of the balloon, inflation fluid in the proximal section of the balloon can flow through the spaces <NUM> between the inner and outer walls of the mounting member, through one or more slots <NUM> in the proximal nose cone portion <NUM>, and into the distal section of the balloon, in the direction of arrows <NUM>.

It should be noted that the location of the threaded portions of the adjustment mechanism <NUM> and the inner shaft <NUM> can be reversed. That is, adjustment mechanism <NUM> can have an externally threaded portion that engages an internally threaded portion of the inner shaft <NUM>. In addition, for embodiments where the balloon <NUM> is initially positioned proximal to the prosthetic valve <NUM>, the adjustment mechanism <NUM> can be used to move the balloon distally relative to the crimped prosthetic valve in order to center the prosthetic valve on the balloon for deployment.

<FIG> show a prosthetic heart valve <NUM>, according to another embodiment. The heart valve <NUM> comprises a frame, or stent, <NUM> and a leaflet structure <NUM> supported by the frame. In particular embodiments, the heart valve <NUM> is adapted to be implanted in the native aortic valve and can be implanted in the body using, for example, the delivery apparatus <NUM> described above. The prosthetic valve <NUM> can also be implanted within the body using any of the other delivery apparatuses described herein. Thus, the frame <NUM> typically comprises a plastically expandable material, such as stainless steel, a nickel based alloy (e.g., a nickel-cobalt-chromium alloy), polymers, or combinations thereof. In other embodiments, the prosthetic valve <NUM>, <NUM> can be a self-expandable prosthetic valve with a frame made from a self-expanding material, such as Nitinol. When the prosthetic valve is a self-expanding valve, the balloon of the delivery apparatus can be replaced with a sheath or similar restraining device that retains the prosthetic valve in a radially compressed state for delivery through the body. When the prosthetic valve is at the implantation location, the prosthetic valve can be released from the sheath, and therefore allowed to expand to its functional size. It should be noted that any of the delivery apparatuses disclosed herein can be adapted for use with a self-expanding valve.

<FIG> is an exploded, perspective view of the distal end section of an alternative embodiment of a delivery device, indicated at <NUM>'. The delivery device <NUM>' shares many similarities with the delivery device <NUM>, and therefore components of the delivery device <NUM>' that are the same as those in the delivery device <NUM> are given the same reference numerals and are not described further. One difference between the delivery device <NUM> and the delivery device <NUM>' is that the latter includes a different mechanism for locking/securing the balloon catheter shaft <NUM> relative to the adjustment knob <NUM>.

Referring to <FIG>, the locking mechanism for the balloon catheter shaft comprises an adjustment knob <NUM> housing an inner nut <NUM>, a washer <NUM> and a ring <NUM> disposed inside the inner nut <NUM>, a biasing member in the form of a coiled spring <NUM>, a pusher element <NUM>, and a shaft engagement member in the form of a collet <NUM>. As best shown in <FIG>, the inner nut <NUM> includes inner threads <NUM> (<FIG>) that engage the external threads of the distal end portion <NUM> of the inner shaft <NUM> (<FIG>). The pusher element <NUM> includes a proximal shaft <NUM> and an enlarged distal end portion <NUM> that bears against the proximal end portion <NUM> of the collet <NUM>. The spring <NUM> is disposed on the shaft <NUM> of the pusher element <NUM> and has a proximal end that bears against the ring <NUM> and a distal end that bears against the distal end portion <NUM> of the pusher element <NUM>.

Referring to <FIG>, the adjustment knob <NUM> is formed with a plurality of longitudinally extending, circumferentially spaced projections <NUM> on the inner surface of the knob. A distal portion of the knob <NUM> includes one or more radially extending projections <NUM> for gripping by a user and a proximal portion of the knob comprises a semi-annular portion <NUM>. The knob <NUM> extends co-axially over the inner nut <NUM> with the projections <NUM> mating with respective grooves <NUM> on the outer surface of the nut <NUM> such that rotation of the knob causes corresponding rotation of the nut <NUM>.

The delivery device <NUM>' can be used in the manner described above in connection with the delivery device <NUM> to deliver a prosthetic valve in the vicinity of the implantation site. To restrain movement of the balloon catheter shaft <NUM> for fine positioning of the prosthetic valve, the knob <NUM> is rotated, which in turn causes rotation of the inner nut <NUM>. The inner nut <NUM> is caused to translate in the distal direction along the external threads on the distal end portion <NUM> of the shaft <NUM>. As the nut <NUM> is moved distally, the nut <NUM> pushes against the ring <NUM>, which in turn pushes against the spring <NUM>. The spring <NUM> presses against the distal end portion <NUM> of the pusher element <NUM>, urging the pusher element against the collet <NUM>. The pushing force of the pusher element <NUM> against the collet causes the fingers <NUM> of the collet to frictionally engage the balloon catheter shaft <NUM>, thereby retaining the balloon catheter shaft relative to the inner shaft <NUM>. In the locked position, rotation of the adjustment knob <NUM> causes the inner shaft <NUM> and the balloon catheter shaft <NUM> to move axially relative to the guide catheter shaft <NUM> (either in the proximal or distal direction, depending on the direction the knob <NUM> is rotated).

The biasing force of the spring <NUM> desirably is sufficient to lock the collet against the balloon catheter shaft with a relatively small degree of rotation of the knob <NUM>, such as less than <NUM> degrees rotation of the knob. In the illustrated embodiment, the knob <NUM> is rotated less than <NUM> degrees from an unlocked position (in which the collet does not retain the balloon catheter shaft) to a locked position (in which the collet frictionally engages and retains the balloon catheter shaft). Conversely, rotating the knob <NUM> in the opposite direction from the locked position to the unlocked position through the same degree of rotation allows the spring <NUM> to release the biasing force against the pusher element and the collet so as to permit axial movement of the balloon catheter shaft relative to the collet.

As best shown in <FIG>, an indicator ring <NUM> is disposed on the shaft <NUM> adjacent the proximal end of the knob <NUM>. The indicator ring <NUM> sits within the semi-annular wall <NUM> of the knob <NUM> and includes an indicator tab <NUM> that extends into the annular space between the ends <NUM> (<FIG>) of the semi-annular wall <NUM>. As best shown in <FIG>, the outer surface of the knob <NUM> can include visual indicia that indicate whether the balloon catheter shaft <NUM> is in a locked state relative to the adjustment knob <NUM>. In the illustrated implementation, for example, a first indicia 182a is located adjacent one end <NUM> of the semi-annular wall <NUM> and a second indicia 182b is located adjacent the other end <NUM> of the semi-annular wall <NUM>. The first indicia 182a is a graphical representation of a closed lock (indicating that the balloon catheter shaft is in a locked state) and the second indicia 182b is a graphical representation of an open lock (indicating that the balloon catheter shaft is in an unlocked state). However, it should be understood that the indicia can take various other forms (text and/or graphics) to indicate the locked and unlocked states.

Since the indicator ring <NUM> is fixed rotationally relative to the knob <NUM>, the indicator tab <NUM> limits rotation of the knob <NUM> through an arc length defined by the annular space between the ends <NUM> of the semi-annular wall <NUM> (about <NUM> degrees in the illustrated embodiment). When the knob <NUM> is rotated in a first direction (counterclockwise in the illustrated example), the indicator tab <NUM> will contact the wall end <NUM> adjacent indicia 182b and prevent further rotation of the knob <NUM>. In this position, the collet <NUM> does not frictionally engage the balloon catheter shaft <NUM>, which can be moved freely relative to the proximal handle portion <NUM>. When the knob <NUM> is rotated in a second direction (clockwise in the illustrated example), the indicator tab <NUM> will contact the wall end <NUM> adjacent indicia 182a and prevent further rotation of the knob <NUM>. In this position, the collet <NUM> is caused to frictionally engage the balloon catheter shaft in the manner described above to restrain axial and rotational movement of the balloon catheter shaft relative to the proximal handle portion <NUM>.

<FIG> show the distal end portion of a balloon catheter <NUM>, according to another embodiment, that can be used to implant an intraluminal implant, such as a stent or a stented prosthetic valve. The features of the balloon catheter <NUM> can be implemented in the delivery apparatuses disclosed herein (e.g., apparatus <NUM> of <FIG>). In the figures, a prosthetic valve is shown schematically and is identified by reference numeral <NUM>. The balloon catheter <NUM> includes a balloon catheter shaft <NUM>. The proximal end of the shaft <NUM> is mounted to a handle (not shown) and the distal end of the shaft mounts a balloon assembly <NUM>.

The balloon assembly <NUM> comprises an inner balloon <NUM> disposed inside an outer balloon <NUM>. The inner balloon <NUM> is shaped to control expansion of the prosthetic valve <NUM> while the outer balloon is shaped to define the final expanded shape of the prosthetic valve. For example, as shown in <FIG>, the inner balloon <NUM> can have a "dog bone" shape when inflated, having bulbous end portions that taper inwardly to form a generally cylindrical center portion of a reduced diameter. The shape of the inner balloon <NUM> helps maintain the position of the prosthetic valve relative to the balloon as the prosthetic valve is expanded due to the larger end portions that restrict movement of the prosthetic valve in the axial directions. The distal end portion of the shaft <NUM> can have openings to allow an inflation fluid to flow from the lumen of the shaft <NUM> into the inner balloon <NUM>.

The inner balloon <NUM> can be formed with small pores or openings that are sized to permit suitable inflation of the inner balloon and allow the inflation fluid to flow outwardly into the space between the two balloons to inflate the outer balloon, as indicated by arrows <NUM>. After the inner balloon is inflated, which partially expands the prosthetic valve <NUM> (<FIG>), the inflation fluid begins inflating the outer balloon <NUM> (<FIG>). Inflation of the outer balloon further expands the prosthetic valve <NUM> to its final desired shape (e.g., cylindrical as shown in <FIG>) against the surrounding tissue. In such a two-stage expansion of the prosthetic valve <NUM>, the position of the prosthetic valve relative to the shaft <NUM> can be controlled due to the inner balloon, which limits axial movement of the prosthetic valve during its initial expansion.

In an alternative embodiment, in lieu of or in addition to the pores or holes in the inner balloon, the inner balloon can be configured to burst at a predetermined pressure (e.g., <NUM>-<NUM> bars) after it is inflated to a desired size. After the inner balloon ruptures, the inflation fluid can begin inflating the outer balloon.

<FIG> discloses a delivery system <NUM> that can be used to implant an expandable prosthetic valve. The delivery system <NUM> is specifically adapted for use in introducing a prosthetic valve into a heart in a transapical procedure, which is disclosed in co-pending Application No. <CIT> (<CIT>). In a transapical procedure, a prosthetic valve is introduced into the left ventricle through a surgical opening in the apex of the heart. The delivery system <NUM> similarly can be used for introducing a prosthetic valve into a heart in a transaortic procedure. In a transaortic procedure, a prosthetic valve is introduced into the aorta through a surgical incision in the ascending aorta, such as through a partial J-sternotomy or right parasternal mini-thoracotomy, and then advanced through the ascending aorta toward heart.

The delivery system comprises a balloon catheter <NUM>, an introducer <NUM>, and a loader <NUM>. The balloon catheter <NUM> comprises a handle <NUM>, an outer flush shaft <NUM> extending from the handle, an articulating main shaft <NUM> extending from the handle <NUM> coaxially through the outer shaft <NUM>, an inner shaft <NUM> extending from the handle coaxially through the articulating shaft <NUM>, an inflatable balloon <NUM> mounted on the shaft <NUM>, and a nose cone <NUM> mounted on the inner shaft <NUM> distal to the balloon.

As best shown in <FIG>, a pusher element, or stop member, <NUM> is mounted on the shaft <NUM> within the proximal portion of the balloon and the nose cone is formed with a stop member <NUM> that extends into the distal portion of the balloon. The spacing between the distal end of the pusher element <NUM> and the proximal end of the stop member <NUM> defines an annular space sized to partially receive a prosthetic valve that is crimped on the balloon. In use, the prosthetic valve is crimped onto the balloon between the pusher element <NUM> and the stop member <NUM> such that the proximal end of the prosthetic valve can abut the pusher element and the distal end of the prosthetic valve can abut the stop member (depicted in the embodiment shown in <FIG>). In this manner, these two elements assist in retaining the position of the prosthetic valve on the balloon as it is inserted through the introducer <NUM>.

As shown in <FIG>, the introducer <NUM> comprises an introducer housing <NUM> and a distal sheath <NUM> extending from the housing <NUM>. The introducer <NUM> is used introduce or insert the balloon catheter <NUM> into a patient's body. As shown in <FIG>, the introducer housing <NUM> houses one or more valves <NUM> and includes a proximal cap <NUM> for mounting the loader. The loader <NUM> provides a coupling between the balloon catheter and the introducer. The loader <NUM> includes two retaining arms <NUM> that engage the proximal cap <NUM> of the introducer. The manner of using a loader to assist in inserting a balloon catheter and prosthetic valve into an introducer is described below with respect to the embodiment shown in <FIG>.

The construction of the handle <NUM> is shown in <FIG>. The handle <NUM> includes a housing <NUM>, which houses a mechanism for effecting controlled deflection, or articulation, of balloon catheter shaft <NUM>. The mechanism in the illustrated embodiment comprises a shaft <NUM>, a sliding mechanism <NUM>, a spring <NUM>, and proximal and distal rack gears <NUM>, <NUM>, respectively. The proximal end portion of the shaft <NUM> is formed with external threads that engage internal threads of two threaded nuts 364a, 364b inside the handle. The shaft <NUM> can rotate within the handle but is restricted from translational movement within the handle. The nuts <NUM> desirably have opposite threads and are disposed on respective portions of the shaft <NUM> that have corresponding external threads. For example, the proximal nut 364a can have left-handed threads and is disposed on left-handed threads on the shaft, while the distal nut 364b can have right-handed threads and is disposed on right-handed threads on the shaft. This causes the nuts <NUM> to translate in opposite directions along the threads of the shaft <NUM> upon its rotation. As best shown in <FIG>, each nut <NUM> has a pair of radially extending flanges <NUM> on diametrically opposite sides of the nut. The inside of the housing is formed with a pair of elongated slots <NUM> (one of which is shown in <FIG>) on opposing inside surfaces of the housing. The opposing flanges <NUM> on each nut <NUM> can extend into respective slots <NUM>, which prevent rotation of the nuts upon rotation of the shaft <NUM>. In this manner, the nuts <NUM> are caused to move lengthwise of the shaft <NUM> upon its rotation.

The distal end portion of the shaft <NUM> supports a proximal spur gear <NUM>, a distal spur gear <NUM>, a proximal clutch <NUM>, and a distal clutch <NUM>. The shaft <NUM> has a flat <NUM> that engages corresponding flats on center bores of the clutches <NUM>, <NUM>, which provides for rotation of the shaft when one of the clutches is engaged and rotated by a respective spur gear, as described below. The sliding mechanism <NUM> includes a user-engageable actuator <NUM>, an elongate arm <NUM> extending from actuator <NUM>, and proximal and distal rings <NUM>, <NUM>, respectively, mounted on the distal end portion of the arm <NUM>. Mounted on the shaft <NUM> and held between the rings is a coil spring <NUM>.

Two pull wires (not shown) extend from the handle through the balloon catheter shaft <NUM> on diametrically opposite sides of the balloon catheter shaft to its distal end portion. A first pull wire has a proximal end secured to the proximal nut 364a inside the handle and a distal end that is secured to the distal end portion of the balloon catheter shaft <NUM>. A second pull wire has a proximal end secured to the distal nut 364b inside the handle and a distal end that is secured to the distal end portion of the balloon catheter shaft <NUM> on a diametrically opposite side from the securement location of the first pull wire.

The housing <NUM> is configured to actuate the deflection (articulation) mechanism inside the handle when it is squeezed by the hand of a user. For example, the housing <NUM> can comprise a lower housing section <NUM> and an upper housing section <NUM>, which can be comprised of two separable housing sections 370a, 370b for ease of assembly. Referring to <FIG>, the lower housing section <NUM> is mounted to the upper housing section <NUM> in a manner that permits the two sections to move toward and apart from each other a limited distance when squeezed by a user's hand, as indicated by arrow <NUM>. The torsion spring <NUM> has one arm 376a that bears against the inner surface of the upper housing portion <NUM> and another arm 376b that bears against the inner surface of the lower housing portion <NUM> to resiliently urge the two housing portions apart from each other. As such, squeezing the handle moves the upper and lower housing portions together and releasing manual pressure allows the housing portions to move apart from each other a limited amount under the spring force. In an alternative embodiment, a portion of the housing can be made of a flexible or deformable material that can deform when squeezed by the hand of a user in order to actuate the deflection mechanism.

The deflection mechanism works in the following manner. Squeezing the handle <NUM> causes the rack gears <NUM>, <NUM> to move in opposite directions perpendicular to shaft <NUM> (due to movement of the upper and lower housing sections), which in turn causes rotation of the corresponding spur gears <NUM>, <NUM> in opposite directions. The sliding mechanism <NUM> can be manually moved between a proximal position, a neutral (intermediate) position, and a distal position. When the sliding mechanism is in the neutral position (<FIG>), the clutches are disengaged from their respective spur gears, such that rotation of the spur gears does not rotate the shaft <NUM>. However, sliding the sliding mechanism <NUM> distally to a distal position pushes the coil spring <NUM> against the distal clutch <NUM> to engage the distal spur gear <NUM>. While the sliding mechanism is held in the distal position, the handle is squeezed and the resulting rotation of the distal spur gear <NUM> is transmitted to the shaft <NUM> to rotate in the same direction, which in turn causes the nuts <NUM> to move in opposite directions along the shaft <NUM> (e.g., toward each other). Translation of the nuts <NUM> in opposite directions applies tension to the first pull wire and introduces slack to the second pull wire, causing the balloon catheter shaft <NUM> to bend or deflect in a first direction. The face of the clutch <NUM> that engages spur gear <NUM> is formed with teeth <NUM> that cooperate with corresponding features of the gear to rotate the clutch and shaft <NUM> when the handle is squeezed, and allow the gear to spin or rotate relative to the clutch when manual pressure is removed from the handle. In this manner, the balloon catheter shaft bends a predetermined amount corresponding to each squeeze of the handle. The deflection of the balloon catheter shaft can be controlled by repeatedly squeezing the handle until the desired degree of deflection is achieved.

The balloon catheter shaft <NUM> can be deflected in a second direction, opposite the first direction by sliding the sliding mechanism <NUM> in the proximal direction, which pushes the coil spring <NUM> against the proximal clutch <NUM> to engage the proximal spur gear <NUM>. While holding the sliding mechanism in the proximal position and squeezing the handle, the proximal spur gear <NUM> rotates the proximal clutch <NUM> in the same direction. Rotation of the proximal clutch is transmitted to the shaft <NUM> to rotate in the same direction, resulting in translation of the nuts <NUM> in opposite directions (e.g., if the nuts move toward each other when the sliding mechanism is in the distal position, then the nuts move away from each other when the sliding mechanism is in the proximal position). The proximal clutch <NUM> is similarly formed with teeth <NUM> that engage the proximal spur gear <NUM> and cause rotation of the proximal clutch and shaft <NUM> only when the handle is squeezed but not when manually pressure is removed from the handle. In any case, movement of the threaded nuts <NUM> applies tension to the second pull wire and introduces slack to the first pull wire, causing the balloon catheter shaft <NUM> to bend in the opposite direction.

<FIG> show an alternative embodiment of a handle, indicated at <NUM>, that can be incorporated in the balloon catheter <NUM> (in place of handle <NUM>). The handle <NUM> comprises a housing <NUM>, which can be formed from two halves 402a, 402b for ease of assembly. Two wheels, or rotatable knobs, 404a, 404b are positioned on opposite sides of the handle. The knobs are mounted on opposite ends of a shaft <NUM> having gear teeth <NUM>. A rotatable, hollow cylinder <NUM> extends lengthwise inside of the handle in a direction perpendicular to shaft <NUM>. The cylinder <NUM> includes external gear teeth <NUM> that engage the gear teeth <NUM> on shaft <NUM>. The inner surface of the cylinder <NUM> is formed with internal threads <NUM>, which can include right-handed and left-handed threads. A proximal threaded nut 416a and a distal threaded nut 416b are disposed inside of the cylinder <NUM> and are mounted for sliding movement on a rail <NUM> that extends co-axially through the cylinder. The nuts 416a, 416b have external threads that are threaded in opposite directions and engage the corresponding right-handed and left-handed threads on the inner surface of the cylinder <NUM>. The rail <NUM> has a flat <NUM> that engages corresponding flats on the inner bores of the nuts 416a, 416b, which allows the nuts to translate along the length of the rail without rotating.

First and second pull wires (not shown) are provided and secured to respective nuts 416a, 416b and the distal end of the balloon catheter shaft <NUM> as previously described. Deflection of the balloon catheter shaft <NUM> in first and second opposing directions can be accomplished by rotating the knobs 404a, 404b (which rotate together) clockwise and counterclockwise. For example, rotating the knobs clockwise produces rotation of the cylinder <NUM> via gear teeth <NUM> engaging gear teeth <NUM>. Rotation of cylinder <NUM> causes the nuts 416a, 416b to move in opposite directions along the rail <NUM> (e.g., toward each other). Translation of the nuts in opposite directions applies tension to the first pull wire and introduces slack to the second pull wire, causing the balloon catheter shaft <NUM> to bend or deflect in a first direction. Rotating the knobs counterclockwise produces rotation of the cylinder <NUM> in a direction opposite its initial rotation mentioned above. Rotation of cylinder <NUM> causes the nuts 416a, 416b to move in opposite directions along the rail <NUM> (e.g., away each other). Translation of the nuts in opposite directions applies tension to the second pull wire and introduces slack to the first pull wire, causing the balloon catheter shaft <NUM> to bend or deflect in a second direction, opposite the first direction.

The handle <NUM> can optional include a pusher actuation mechanism <NUM> that is configured to move a pusher device adjacent the distal end of the balloon catheter. The pusher device extends partially over the balloon and holds the prosthetic valve in place on the balloon as the prosthetic valve and balloon catheter are inserted through the introducer. A pusher device is disclosed in co-pending Application No. <CIT>. The actuation mechanism <NUM> is pivotably connected to a linkage arm <NUM>, which in turn is pivotably connected to a proximal holder <NUM> of the pusher device (not shown). The pusher device can extend from the proximal holder <NUM> to the balloon <NUM>. Moving the actuation mechanism <NUM> to a distal position moves the pusher device in a position partially extending over the balloon <NUM> and holding the prosthetic valve in place on the balloon for insertion through the introducer <NUM>. Moving the actuation mechanism <NUM> to a proximal position moves the pusher device proximally away from the balloon and the prosthetic valve once inside the heart so that the balloon can be inflated for deployment of the prosthetic valve. If a movable pusher device is not used (as in the illustrated balloon catheter <NUM>), then the pusher actuation mechanism <NUM> would not be needed. For example, in lieu of or in addition to such a pusher device, stop members <NUM>, <NUM> inside the balloon can be used to retain the position of the prosthetic valve on the balloon (<FIG> and <FIG>).

<FIG> show another embodiment of a handle, indicated at <NUM>, that can be incorporated in the balloon catheter <NUM> (in place of handle <NUM>). The handle <NUM> comprises a housing <NUM>, which can be formed from multiple housing sections, including first and second distal housing portions <NUM>, <NUM>, respectively, that form a distal housing space, and first and second proximal housing portions <NUM>, <NUM>, respectively, that form a proximal housing space. The housing houses a proximal cylinder <NUM> and a distal cylinder <NUM>, which house proximal and distal nuts <NUM>, <NUM>, respectively. The nuts are disposed on a rail <NUM> that extends co-axially through the cylinders <NUM>, <NUM>. The cylinders <NUM>, <NUM> have opposing internal threads, e.g., the proximal cylinder can have right-handed threads and the distal cylinder can have left-handed threads. The cylinders <NUM>, <NUM> are secured to each other end-to-end (e.g., with a frictional fit between the distal end of the proximal cylinder and the proximal end of the distal cylinder) so that both rotate together. In other embodiments, the cylinders <NUM>, <NUM> can be formed as a single cylinder having left-handed and right-handed threads as used in the handle <NUM> described above.

A user-engageable, rotatable knob <NUM> is mounted on the outside of the housing <NUM> and engages the proximal cylinder <NUM> (e.g., through an annular gap in the housing) such that rotation of the knob <NUM> causes corresponding rotation of the cylinders <NUM>, <NUM>. The deflection mechanism of this embodiment works in a manner similar to that shown in <FIG> to alternatively apply tension and introduce slack in first and second pull wires (not shown) secured to the nuts <NUM>, <NUM>, respectively. For example, rotating the knob <NUM> in a first direction causes the nuts to translate in opposite directions along the rail <NUM> (e.g., toward each other), which is effective to apply tension to the first pull wire and introduce slack to the second pull wire, causing the balloon catheter shaft <NUM> to bend or deflect in a first direction. Rotating the knob <NUM> in a second direction causes the nuts to translate in opposite directions (e.g., away from each other), which is effective to apply tension to the second pull wire and introduce slack to the first pull wire, causing the balloon catheter shaft <NUM> to bend or deflect in a second direction, opposite the first bending direction.

<FIG> discloses a delivery apparatus <NUM>, according to the invention, that can be used to implant an expandable prosthetic heart valve. The delivery apparatus <NUM> is specifically adapted for use in introducing a prosthetic valve into a heart in a transapical or transaortic procedure. A delivery system for implanting a prosthetic heart valve can comprise the delivery apparatus <NUM>, an introducer <NUM> (<FIG>), and a loader <NUM> (<FIG>).

Referring to <FIG>, the delivery apparatus <NUM> in the illustrated form is a balloon catheter comprising a handle <NUM>, a steerable shaft <NUM> extending from the handle <NUM>, an inner shaft <NUM> extending from the handle <NUM> coaxially through the steerable shaft <NUM>, an inflatable balloon <NUM> extending from the distal end of the steerable shaft <NUM>, a proximal shoulder, or stop member, <NUM> extending from the distal end of the steerable shaft <NUM> into the proximal end region of the balloon, a nose cone <NUM> mounted on the distal end of the inner shaft <NUM>, and a distal shoulder, or stop member, <NUM> mounted on the inner shaft <NUM> within the distal end region of the balloon. The distal stop member <NUM> can be an integral extension of the nose cone <NUM> as shown. The proximal stop member <NUM> can have a proximal end portion <NUM> secured to the outside surface of the distal end portion of the steerable shaft <NUM>. The balloon <NUM> can have a proximal end portion <NUM> and a distal end portion <NUM>, with the proximal end portion <NUM> being secured to the outer surfaces of the shaft <NUM> and/or the end portion <NUM> of the proximal stop <NUM> and the distal end portion <NUM> being secured to the outer surface of a distal end portion <NUM> of the distal stop member <NUM>.

As best shown in <FIG>, the proximal end portion <NUM> of the proximal stop member <NUM> includes one or more openings <NUM> for inflation fluid formed in the annular wall between the outer surface of the inner shaft <NUM> and the inner surface of the outer shaft <NUM>. The openings <NUM> allow inflation fluid to flow outwardly from the space between the inner shaft <NUM> and the outer shaft <NUM> into the balloon in the distal direction.

The proximal stop member <NUM> has a distal end portion <NUM> in form of a substantially cone-shaped member, and the distal stop member <NUM> has a proximal end portion <NUM> of the same shape. The spacing between the cone-shaped members <NUM>, <NUM> defines an annular space sized to at least partially receive a prosthetic valve that is crimped on the balloon. In use, as shown in <FIG>, the prosthetic valve <NUM> is crimped onto the balloon between the cone-shaped members <NUM>, <NUM> such that the prosthetic valve is retained on the balloon between the cone-shaped members as the prosthetic valve is advanced through the introducer. Desirably, the spacing between the cone-shaped members <NUM>, <NUM> is selected such that the prosthetic valve is slightly wedged between the cone-shaped members with the non-inflated balloon extending between the proximal end of the prosthetic valve and the proximal member <NUM> and between the distal end of the prosthetic valve and the distal member <NUM>. In addition, the maximum diameter of the members <NUM>, <NUM> at their ends adjacent the ends of the prosthetic valve desirably is about the same as or slightly greater than the outer diameter of the frame of the prosthetic valve <NUM> when crimped onto the balloon.

As further shown in <FIG>, each of the cone-shaped members <NUM>, <NUM> desirably is formed with one or more slots <NUM>. In the illustrated embodiment, each of the cone-shaped members <NUM>, <NUM> has three such slots <NUM> that are equally angularly spaced in the circumferential direction. The slots <NUM> facilitate radial compression of the cone-shaped members <NUM>, <NUM>, which is advantageous during manufacturing of the delivery device and during crimping of the prosthetic valve. In particular, the proximal and distal ends <NUM>, <NUM> of the balloon may be relatively smaller than the maximum diameter of the cone-shaped members <NUM>, <NUM>. Thus, to facilitate insertion of the cone-shaped members <NUM>, <NUM> into the balloon during the assembly process, they can be radially compressed to a smaller diameter for insertion into the balloon and then allowed to expand once inside the balloon. When the prosthetic valve is crimped onto the balloon, the inside surfaces of the crimping device (such as the surfaces of crimping jaws) may contact the cone-shaped members <NUM>, <NUM> and therefore will radially compress the cone-shaped members along with the prosthetic valve. Typically, the prosthetic valve will undergo a small amount of recoil (radial expansion) once removed from the crimping device. Due to the compressibility cone-shaped members <NUM>, <NUM>, the prosthetic valve can be fully compressed to a crimped state in which the metal frame of the prosthetic valve has an outer diameter equal to or less than the maximum diameter of the cone-shaped members (accounting for recoil of the prosthetic valve).

The slots <NUM> in the cone-shaped members <NUM>, <NUM> also allow inflation fluid to flow radially inwardly through the cone-shaped members and through the region of the balloon extending through the crimped prosthetic valve in order to facilitate expansion of the balloon. Thus, inflation fluid can flow from a proximal region of the balloon, inwardly though slots <NUM> in proximal stop member <NUM>, through the region of the balloon extending through the prosthetic valve, outwardly through slots <NUM> in distal stop <NUM>, and into a distal region of the balloon. Another advantage of the distal stop member <NUM> is that it serves a transition region between the nose cone and the prosthetic valve. Thus, when the prosthetic valve is advanced through the leaflets of a native valve, the distal stop member <NUM> shields the distal end of the prosthetic valve from contacting the surrounding tissue, which can otherwise dislodge or prevent accurate positioning of the prosthetic valve prior to deployment.

The construction of the handle <NUM> is shown in <FIG>. The handle <NUM> comprises a housing <NUM>, which can be formed from multiple housing sections. The housing <NUM> houses a mechanism for effecting controlled articulation/deflection of the shaft <NUM>. The mechanism in the illustrated embodiment comprises a threaded shaft <NUM>, and a threaded nut <NUM> disposed on the shaft. The proximal end portion of the shaft <NUM> is formed with external threads that engage internal threads of the threaded nut <NUM>. The shaft <NUM> can rotate within the handle but is restricted from translational movement within the handle. The nut <NUM> has opposing flanges <NUM> (one of which is shown in <FIG>), which extend into respective slots formed on the inside surfaces of the housing to prevent rotation of the nut. In this manner, the nut <NUM> translates along the threads of the shaft <NUM> upon rotation of the shaft.

The distal end portion of the shaft <NUM> supports user-engageable, rotatable knob <NUM>. The shaft <NUM> is coupled to the knob <NUM> such that rotation of the knob causes corresponding rotation of the shaft <NUM>. A pull wire <NUM> extends from the handle through the balloon catheter shaft <NUM> on one side of the balloon catheter shaft to its distal end portion. The pull wire <NUM> has a proximal end secured to the threaded nut <NUM> inside the handle and a distal end that is secured to the distal end portion of the balloon catheter shaft <NUM>. The articulation mechanism of this embodiment works by rotating the knob <NUM> in one direction, which causes the threaded nut <NUM> to translate along the shaft <NUM>, which is effective to apply tension to the pull wire causing the balloon catheter shaft <NUM> to bend or articulate in a predetermined direction. Rotating the knob <NUM> in the opposite direction causes to the nut <NUM> to translate in the opposite direction, thereby releasing tension in the pull wire, which allows the shaft <NUM> to deflect in the opposite direction under its own resiliency. In alternative embodiments, another threaded nut and respective pull wire can be provided in the housing to allow for bi-directional steering of the shaft <NUM>, as described above in connection with the embodiments of <FIG>.

<FIG> is a perspective view of the introducer <NUM>, which comprises an introducer housing assembly <NUM> and a sheath <NUM> extending from the housing assembly <NUM>. The introducer <NUM> is used to introduce or insert the delivery apparatus <NUM> into a patient's body. In a transapical procedure, for example, the sheath <NUM> is inserted through surgical incisions in the chest and the apex of the heart to position the distal end of the sheath in the left ventricle (such as when replacing the native aortic valve). The introducer <NUM> serves as a port or entry point for inserting the delivery apparatus into the body with minimal blood loss. As shown in <FIG>, the introducer housing <NUM> houses one or more valves <NUM>, and includes a distal cap <NUM> to secure sheath <NUM> to the housing <NUM> and a proximal cap <NUM> for mounting the loader <NUM>.

<FIG> are respective and cross-sectional views of the loader <NUM>, which is used to protect the crimped prosthesis during insertion into the introducer <NUM>. The loader <NUM> in the illustrated configuration comprises a distal loader assembly <NUM> and a proximal loader assembly <NUM>. The distal loader assembly <NUM> and proximal loader assembly <NUM> can be secured to each other by mating female and male threads <NUM> and <NUM>, respectively. The distal loader assembly <NUM> comprises a loader tube <NUM> and a loader distal cap <NUM>. The proximal loader assembly <NUM> comprises a loader housing <NUM>, a button valve <NUM>, a washer <NUM>, two disc valves <NUM>, and a proximal loader cap <NUM>. The distal loader cap <NUM> can be formed with a lip <NUM> that is configured to engage the proximal cap <NUM> of the introducer <NUM> as shown in <FIG>.

In use, the proximal loader assembly <NUM> (apart from the distal loader assembly <NUM>) can be placed on the balloon catheter shaft <NUM> prior to placing the prosthetic valve on the balloon and the crimping the prosthetic valve to avoid passing the crimped prosthetic valve through the sealing members <NUM> inside the housing <NUM>. After the prosthetic valve is crimped onto the balloon, the distal loader assembly <NUM> is slid over the crimped prosthetic valve and secured to the proximal loader assembly <NUM> (by screwing threads <NUM> into threads <NUM>). As shown in <FIG>, the loader tube <NUM> (while covering the crimped prosthetic valve) can then be inserted into and through the introducer housing <NUM> so as to extend through the internal sealing members <NUM> (<FIG>). The loader tube <NUM> therefore prevents direct contact between the sealing members <NUM> of the introducer and the crimped prosthetic valve. The loader <NUM> can be secured to the introducer <NUM> by pressing the annular lip <NUM> of the loader into the proximal cap <NUM> of the introducer. After insertion of the loader tube into the introducer, the prosthetic valve can be advanced from the loader tube, through the sheath <NUM>, and into a region with the patient's body (e.g., the left ventricle).

As best shown in <FIG>, the proximal cap <NUM> of the introducer comprises first and second diametrically opposed ribbed portions <NUM> and first and second diametrically opposed, deflectable engaging portions <NUM> extending between respective ends of the ribbed portions. When the loader <NUM> is inserted into the introducer <NUM>, the lip <NUM> of the loader snaps into place on the distal side of the engaging portions <NUM>, which hold the loader in place relative to the introducer. In their non-deflected state, the ribbed portions <NUM> are spaced slightly from the adjacent surfaces of the cap <NUM> of the loader. To remove the loader from the introducer, the ribbed portions <NUM> are pressed radially inwardly, which causes the engaging portions <NUM> to deflect outwardly beyond the lip <NUM>, allowing the loader and the introducer to be separated from each other.

Fluid (e.g., saline) can be injected into the loader <NUM> through a lured port <NUM>, which when pressurized by fluid will allow for fluid flow in a single direction into the loader housing. Alternatively, fluid (e.g., blood, air and/or saline) can be removed from the loader <NUM> by depressing the crossed portion of the button valve <NUM>, which creates an opening between the valve <NUM> and the loader housing. As best shown in <FIG>, the button <NUM> in the illustrated embodiment comprises an elastomeric annular ring <NUM> and a user-engageable projection <NUM> that extends outwardly through an opening <NUM> in the loader housing <NUM>. The ring <NUM> seals the opening <NUM> and another opening <NUM> in the loader housing that communicates with the port <NUM>. When a pressurized fluid is introduced into the port <NUM>, the pressure of the fluid causes the adjacent portion of the ring <NUM> to deflect inwardly and away from its position sealing opening <NUM>, allowing the fluid to flow into the loader. Alternatively, to remove fluid from the loader, a user can depress projection <NUM>, which causes the adjacent portion of the ring <NUM> to deflect inwardly and away from its position sealing the opening <NUM>, allowing fluid in the loader to flow outwardly through the opening <NUM>.

For purposes of this description, certain aspects, advantages, and novel features of the embodiments of this disclosure are described herein. The disclosed methods, apparatuses, and systems 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 sub-combinations with one another. The methods, apparatuses, and systems are not limited to any specific aspect or feature or combination thereof, nor do the disclosed embodiments require that any one or more specific advantages be present or problems be solved.

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. 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.

Claim 1:
A delivery device (<NUM>) for implantation of a prosthetic heart valve (<NUM>) through a body of a patient and into the heart, the prosthetic heart valve (<NUM>) being radially expandable from a radially compressed state to a radially expanded state, the delivery device (<NUM>) comprising:
an inflatable balloon (<NUM>); and
an outer shaft (<NUM>) having a lumen and an inner shaft (<NUM>) extending through the lumen of the outer shaft (<NUM>), wherein a proximal stop (<NUM>) is attached to a distal end of the outer shaft (<NUM>), and wherein a distal stop (<NUM>) is attached to an outer surface of the inner shaft (<NUM>);
wherein the proximal stop (<NUM>) and the distal stop (<NUM>) are configured to limit longitudinal movement of the prosthetic heart valve (<NUM>) relative to the balloon (<NUM>) while the prosthetic heart valve (<NUM>) is mounted over the balloon (<NUM>) in the radially compressed state between the proximal stop (<NUM>) and the distal stop (<NUM>), the prosthetic heart valve (<NUM>) having a proximal end and a distal end;
wherein the proximal stop (<NUM>) and the distal stop (<NUM>) each comprise an end portion (<NUM>, <NUM>) positioned within the balloon (<NUM>) and configured to be positioned adjacent a respective end of the prosthetic heart valve (<NUM>) when the prosthetic heart valve (<NUM>) is radially compressed between the proximal and distal stops (<NUM>, <NUM>), each of the end portions (<NUM>, <NUM>) are in form of a substantially cone-shaped member; and
wherein the proximal stop (<NUM>) is configured to abut the proximal end of the prosthetic heart valve (<NUM>) and the distal stop (<NUM>) is configured to abut the distal end of the prosthetic heart valve (<NUM>).