Patent Description:
It is a known to treat problems that might occur in one or more valves of a human heart, such as stenosis, by replacement of the affected valve or valves with an appropriately configured prosthetic heart valve. Replacement of the mitral, aortic, tricuspid and pulmonary valves is possible. In each case, replacement of an affected valve generally involves the delivery of a prosthetic valve in a volume reduced or collapsed state to a desired position within the heart which is at or adjacent to the location of the affected valve. The prosthetic valve is then manipulated so as to adopt a volume increased or non-collapsed state so as to be superimposed over, and take the function of, the affected valve.

Taking the example of the mitral valve, a known prosthetic mitral valve is arranged to regulate blood flow between two chambers, the left atrium and left ventricle of a human heart. The prosthetic mitral valve comprises a stent, a cylindrical cuff, leaflets and a flange formed of braided nitinol wires. The leaflets are operable between a closed status in which the leaflets prevent the flow of blood from the left ventricle to the left atrium and an open status in which the leaflets maximally enable the flow of blood through the prosthetic valve, i.e. the leaflets restrict the flow of blood through the prosthetic valve minimally. The prosthetic mitral valve is collapsible for easy delivery and expandable in radial direction to be anchored and functioning in the heart. The flange itself is formed of two overlaying sheets that are joined together. The flange is formed of a braided material.

The flange comprises a flared portion and a body portion and is connected to the stent at a coupling portion. On the side of the ventricle the stent protrudes into the ventricle beyond the coupling portion. On the atrial side of the prosthetic heart valve the flared portion is directly connected to the coupling portion, whereas at the ventricular side the body portion is between the coupling portion and the flared portion. This means that the prosthetic heart valve has an asymmetric configuration about a central longitudinal axis because the flange forms different shapes on the atrial and ventricular sides of the prosthetic heart valve. Consequently, different portions of the stent on the ventricular side are exposed. In addition, the prosthetic mitral valve has anchoring arms connected to the stent on the atrial side, whereas it has stabilizing wires connected to the flange on the ventricular side for anchoring.

Preferably a prosthetic mitral valve is delivered via a catheter in a procedure sometimes referred to as transcatheter mitral valve replacement (TMVR) wherein transcatheter refers to the delivery by catheter. Transcatheter mitral valve replacement is a relatively new field, and transseptal delivery of the TMVR device is becoming more preferred due to reduced invasiveness.

Typically, transseptal unsheathing of TMVR devices is conducted in a sub or intraannular fashion, meaning that part of the device is unsheathed inside the ventricle before the device is implanted on the target area. Insufficient left ventricular volume is a major exclusion criterion for TMVR devices -- the left ventricle should be able to accommodate the TMVR device during unsheathing without interfering with the chordal apparatus and/or ventricular endocardium. In addition, insufficient left ventricular volume can result increase the risk of obstruction of the left ventricular outflow tract (LVOT) by the TMVR device after deployment.

The above description of transcatheter mitral valve replacement is provided by way of example only and is not intended to be limiting upon the scope of the claimed invention. As noted above, other heart valves can be replaced. Taking the example of replacement of the aortic valve, transsubclavian or transfemoral delivery may be employed. With regard to replacement of the tricuspid valve, transjugular delivery may be employed. <CIT> discloses a prosthetic heart valve.

The present invention relates to the configuration of a prosthetic heart valve within a delivery device such as a catheter or a delivery capsule that enables supra-annular unsheathing of the prosthetic heart valve as opposed to sub-annular unsheathing.

According to a first aspect of the present invention there is provided a method of loading a prosthetic heart valve into a delivery device, the prosthetic heart valve including:.

The circumferential flange is inverted such that its orientation relative to the inner frame when the prosthetic heart valve is in the radially compressed condition is opposite to that when the prosthetic heart valve is in the radially uncompressed condition. More specifically, a circumferential surface of the flange which faces inwardly and towards the inner frame when the prosthetic heart valve is in the radially uncompressed condition is repositioned so as to face radially outwardly and away from the inner frame when the prosthetic heart valve is in the radially compressed condition. Similarly, a circumferential surface of the flange which faces outwardly and away from the inner frame when the prosthetic heart valve is in the radially uncompressed condition is repositioned so as to face radially inwardly and towards the inner frame when the prosthetic heart valve is in the radially compressed condition.

The loading of the prosthetic heart valve into the delivery device may utilise a tapered conduit having a first aperture, a second aperture and a tapered lumen extending between the first aperture and the second aperture, wherein the diameter of the first aperture is greater than the second aperture, and wherein further the diameter of the first aperture is greater than the diameter of the inner frame and less than the diameter of the circumferential flange.

In such an instance the method may comprise the further steps of:.

The step of inverting the circumferential flange includes the step of;.

It will be understood that the portion of the tapered conduit defining the first opening acts as a circumferential abutment surface which bears against the circumferential flange as the prosthetic heart valve is moved into the tapered lumen. The aforementioned circumferential abutment surface bears against the flange, and causes inversion of the flange, as the result of continued movement of the prosthetic heart valve into the tapered conduit.

The prosthetic heart valve may include a plurality of hooks which are attached to the inner frame and which overlie the braided wire mesh when the valve is in the radially uncompressed condition. In such an instance, the step of inverting the circumferential flange results in the braided wire mesh moving to a position where it overlies the hooks.

The step of moving the prosthetic heart valve into the lumen of the delivery device may be achieved by the use of traction wires which are releasably attachable to the inner frame of the valve. Alternatively, other methods may be employed to move the prosthetic heart valve into the lumen of the delivery device. These may include, but not be limited to, manual manipulation, the use of a plunger tool, or the use of an iris crimper.

The delivery device may be a catheter. Alternatively, the delivery device may be a capsule which is configured to retain the valve in radially compressed condition. The capsule may form an integral part of a catheter. Alternatively, the capsule may be mountable or otherwise connectable to a catheter.

According to another aspect of the present invention there is provided the combination of a delivery device and a prosthetic heart valve in a radially compressed condition and located within the delivery device, wherein the prosthetic heart valve includes:.

The part of the radially compressed valve that is most distal to the distal aperture of the delivery device may be the inner frame of the valve.

The prosthetic heart valve has a radially uncompressed condition and may include a plurality of hooks which are attached to the inner frame and which overlie the braided wire mesh when the valve is in the radially uncompressed condition. In such an embodiment the valve is orientated within the delivery capsule in the radially compressed condition such that the hooks are positioned radially inwardly of the braided wire mesh, and the braided wire mesh overlies the hooks.

The delivery device may be a catheter. Alternatively, the delivery device may be a capsule which is configured to retain the valve in radially compressed condition. The capsule may form an integral part of a catheter. Alternatively, the capsule may be mountable or otherwise connectable to a catheter.

According to an example an example there is provided a method of unsheathing a prosthetic heart valve, the method comprising the steps of:
providing a delivery device having a prosthetic heart valve in a radially compressed condition located within the delivery device, wherein the prosthetic heart valve includes:.

Such a method of unsheathing the valve may be performed outside of the body of a patient for the purposes of familiarisation and training of medical practitioners.

The prosthetic heart valve may have a radially uncompressed condition and include a plurality of hooks which are attached to the inner frame and which overlie the braided wire mesh when the prosthetic heart valve is in the radially uncompressed condition; the prosthetic heart valve being orientated within the catheter or delivery capsule in the radially compressed condition such that the hooks are positioned radially inwardly of the braided wire mesh, and the braided wire mesh overlies the hooks;
wherein the step of continuing the longitudinal advancement of the prosthetic heart valve to revert the circumferential flange to the non-inverted state moves the hooks from the position where the hooks are radially inwardly of the braided wire mesh to the position where the hooks overlie the braided wire mesh.

An embodiment of the present invention will now be described with reference to the accompanying figures in which;.

Referring to <FIG>, a prosthetic heart valve <NUM> comprises an inner frame <NUM>, two leaflets <NUM> and a braided wire mesh <NUM>. The heart valve <NUM> itself shown is described in greater detail in co-pending International patent application no <CIT>.

<FIG> depicts the prosthetic heart valve <NUM> in radially uncompressed condition. In the example shown, the prosthetic heart valve <NUM> is a prosthetic mitral valve suitable for transcatheter mitral valve replacement (TMVR). Moreover, when used according to the present invention, it is suitable for transseptal delivery. Description of the present invention with reference to TMVR is done by way of example only and is not intended to be limiting upon the scope of the claimed invention. As will be described in greater detail below, the present invention may be used in connection with other valve types and procedures.

The inner frame <NUM> is made by laser cutting mazes or apertures in a metal tube. The metal is a pseudoelastic metal, in this case nitinol, a nickel titanium metal alloy. Alternatively, the metal may be an alloy of Nickel and Cobalt.

The inner frame <NUM> has a tubular shape comprising a lumen <NUM> that extends from an upstream side <NUM> to a downstream side <NUM> of the prosthetic heart valve <NUM>.

Upstream <NUM> side and downstream side <NUM> are used here even if the prosthetic heart valve is not implanted or even near a fluid as the prosthetic heart valve <NUM> is arranged to regulate fluid flow between the upstream <NUM> side and downstream side <NUM>.

The radially uncompressed condition corresponds to a condition in which the prosthetic heart valve is not constrained radially and placed on a horizontal surface with its downstream side <NUM> or its upstream side <NUM> facing the horizontal surface.

The braided wire mesh <NUM> is arranged outside the inner frame <NUM>. The braided wire mesh forms a skeleton of a flange <NUM>. The flange <NUM> comprises a single layer of a braided wire mesh <NUM> that is coupled to the inner frame <NUM> at a coupling portion <NUM> of the flange. The braided wire mesh (and since that forms the skeleton of the flange <NUM> therefore the flange <NUM> also) further comprises a flared portion <NUM> and a body portion <NUM>. The body portion <NUM> forms the connection between the flared portion <NUM> and the coupling portion <NUM>. In the radially uncompressed condition, the flared portion <NUM> is closest of the <NUM> portions (i.e. the coupling portion <NUM>, the body portion <NUM> and the flared portion <NUM>) to the upstream side <NUM> and the coupling portion <NUM> is closest of the <NUM> portions to the downstream side <NUM>.

The flange <NUM> further comprises a layer <NUM> of elastic material that is attached to the braided wire mesh <NUM> by stitches (stitches not shown). Alternatively, the layer <NUM> of elastic material may be attached to the braided wire mesh <NUM> by alternative means, for example by adhesive.

The elastic material is a polyurethane fabric. The braided wire mesh <NUM> comprises a braided wire mesh surface <NUM> that at the body portion <NUM> faces the inner frame <NUM>. The layer <NUM> of elastic material is attached to the braided wire mesh surface <NUM>.

The prosthetic heart valve <NUM> forms a cavity <NUM> that is surrounded by the braided wire mesh <NUM> (and the flange <NUM>) and the inner frame <NUM>. The inner frame <NUM> comprises an outer frame surface <NUM> that faces the cavity <NUM>. The cavity <NUM> is not completely surrounded and has an opening <NUM> on the upstream side <NUM>.

The lumen <NUM> is enclosed by a lumen wall. The lumen wall comprises the inner frame <NUM> and a further layer <NUM> of elastic material. The elastic material is a polyurethane fabric. The further layer <NUM> of elastic material is attached to the outer surface <NUM> by stitches (stitches not shown). Alternatively, the further layer <NUM> of elastic material may be attached to the outer surface <NUM> by alternative means, for example by adhesive.

The layer <NUM> of elastic material and the further layer <NUM> of elastic material are made from extensible fabric that has a low permeability for blood. The layer <NUM> of elastic material therefore forms a liner with low permeability for blood and the further layer <NUM> of elastic material therefore forms a further liner with low permeability for blood.

The permeability is chosen such that the material is not permeable below a blood pressure of at least <NUM> Hg which pressure corresponds to the pressure required to open the aortic valve.

At the coupling portion <NUM> the layer <NUM> of elastic material and the further layer <NUM> of elastic material are connected to each other by stitches to form a blood tight seam. The blood tight seam functions as a seal. The leaflets <NUM> are arranged in the lumen <NUM> and is arranged to regulate the fluid flow. The leaflets <NUM> preferably are of bovine pericardial tissue.

As the inner frame <NUM> and the flange <NUM> are lined with the layer <NUM> of elastic material and the further layer <NUM> of elastic material, fluids can only pass through the prosthetic heart valve <NUM> through the lumen and thus the leaflet assembly <NUM>.

The inner frame <NUM> is made by laser cutting mazes in a metal tube such that the shape of the inner frame <NUM> in the radially uncompressed condition is constant along the axial direction. There may however be some effects, such as flaring or tapering at the ends after incorporation into the prosthetic valve <NUM>.

The inner frame <NUM> and the flange <NUM> each have a rotationally symmetric circumference around an axis <NUM> extending from the upstream side <NUM> to the downstream side <NUM>. This is shown in <FIG>. Having a rotationally symmetric circumference around the same axis, means that the inner frame <NUM> and the flange <NUM> are concentric.

The braided wire mesh <NUM> is formed by a single continuous wire <NUM> which in the example shown is made from a pseudoelastic metal, in this case nitinol.

The prosthetic heart valve <NUM> further comprises a plurality of hooks <NUM> attached to the inner frame <NUM> on the downstream side <NUM>. This is shown in <FIG>. The hooks <NUM> point away from the lumen <NUM> and towards the upstream side <NUM>. The hooks <NUM> are arranged to capture native leaflets <NUM> when unsheathed in a mitral valve annulus of a human heart. This is shown in <FIG>. The hooks <NUM> are distributed at rotationally symmetric positions around the axis <NUM>.

The hooks <NUM> each comprise an attachment end <NUM> where they are attached to the inner frame <NUM>. The hooks <NUM> are formed together with the inner frame <NUM>, however, they may be produced separately and attached to the inner frame <NUM> later. The hooks <NUM> further each comprise a top <NUM> at side of the hooks opposite to the attachment end <NUM>.

The hooks <NUM> further each comprise a hook body which has an elongated shape. The hooks <NUM> comprise a surface <NUM> that at the hook body partially faces the flange <NUM>. The hooks <NUM> are curved and the surface of the top <NUM> partially faces the upstream side <NUM> and partially faces radially outward.

The hooks <NUM> each comprise two legs <NUM>. This is shown in <FIG> which depicts a frontal view in the direction of the axis <NUM> where the hook <NUM> has been depicted as if it was made flat for the purpose of explanation, i.e. in the drawing the hook does not point away from the lumen <NUM> but the legs are parallel to the lumen <NUM>.

The legs have a centre line <NUM> that extends between the attachment end <NUM> and the top <NUM>. The dimension of the hook legs <NUM> perpendicular to the centre line <NUM> tapers towards the top <NUM>.

Similarly, the dimension of the hook legs <NUM> perpendicular to the centre line <NUM> tapers at the attachment end <NUM> by becoming smaller towards the attachment end <NUM>.

As shown in <FIG>, the flange has a first dimension (D1) along the axis <NUM>. The inner frame <NUM> has a second dimension (D2) along the axis <NUM>. The second dimension (D2) is larger than the first dimension (D1) in this radially uncompressed condition.

The valve <NUM> will now be described in a collapsed condition. This will be done with reference to <FIG>. In these figures the prosthetic heart valve <NUM> is depicted in a delivery device such as a catheter <NUM>. In <FIG> the layer <NUM> of elastic material and the further layer <NUM> of elastic material are not shown for clarity reasons.

The catheter <NUM> has a cylindrical catheter wall <NUM> defining a lumen. The collapsed condition is not a stable condition and can be maintained only as long as the prosthetic heart valve <NUM> stays inserted in the catheter <NUM> and is exposed to radial pressure by the catheter wall <NUM>.

The inner frame <NUM> is radially collapsed over its entire length.

The braided wire mesh <NUM> and thereby the flange <NUM> is also radially collapsed over the entire length in the axial direction of the braided wire mesh <NUM>. From the collapsed condition the prosthetic heart valve <NUM> can return to the radially uncompressed condition and the target condition without any permanent deformations because the inner frame <NUM> and the braided wire mesh <NUM> are made of nitinol which has pseudoelastic properties. As the flange <NUM> comprises a layer <NUM> of elastic material to restrict the flow of blood, and the valve lumen wall comprises a further layer <NUM> elastic material, these layers are arranged to return to the radially uncompressed and target condition elastically as well.

In this case the hooks <NUM> are folded back and extend both away from the inner frame <NUM> and the flange <NUM>.

In this collapsed state, the first dimension (D1) is larger than the second dimension (D2). This is the result of the braided wire mesh <NUM> collapsing inwardly.

The valve <NUM> will now be described in a target condition. This will be done with reference to <FIG>. In this figure the prosthetic heart valve <NUM> is depicted as unsheathed in the annulus <NUM> of a mitral valve in a human heart. The annulus <NUM> is an opening in the heart wall <NUM> separating the left atrium <NUM> and the left ventricle <NUM> of the human heart. In <FIG> the layer <NUM> of elastic material and the further layer <NUM> of elastic material are not shown for clarity reasons.

The target condition is a condition wherein only a part of the length of the body portion <NUM> of the flange <NUM> along the axis <NUM> is radially compressed.

A condition in which the prosthetic heart valve <NUM> is unsheathed and in use to regulate fluid flow, for instance as a mitral valve in a human heart corresponds to the target condition.

The heart wall <NUM> exerts radial pressure to the braided wire mesh <NUM> of the flange <NUM> at the annulus <NUM>. This pressure is not symmetrically applied and the shape of the heart wall <NUM> in the atrium is not constant around the axis <NUM>. Therefore, the flared portion <NUM> reaches into the left atrium <NUM> differently around the axis <NUM>.

Between the hooks <NUM> and the braided wire mesh <NUM> two native leaflets <NUM> are captured. Even though the exerted radial pressure is asymmetric, the resulting radial compression of the braided wire mesh <NUM> and thereby of the flange <NUM> causes the body portion <NUM> of the braided wire mesh <NUM> to elongate in axial direction such that the first dimension (D1) increases.

The first dimension (D1) is larger than the second dimension (D2) in this target condition. In addition, the tops <NUM> of the hooks <NUM> are positioned against the heart wall <NUM>. As the prosthetic heart valve <NUM> in radially uncompressed condition has the flared portion <NUM> closer to the hooks <NUM>, the flared portion <NUM> exerts a force that pushes the top <NUM> of the hooks against the heart wall <NUM> which helps anchor the prosthetic heart valve <NUM>.

It will be appreciated that the unsheathing of the valve <NUM> from the collapsed condition within the catheter <NUM> to the target condition in the mitral valve annulus <NUM> requires the catheter <NUM> to be positioned at least partially through the annulus <NUM> and into the ventricle <NUM>. As noted above, this may not be possible for certain patients due to insufficient ventricular volume.

The conventional manner in which the valve <NUM> is unsheathed from the catheter <NUM>, and described above with reference to <FIG>, requires unsheathing of the hooks <NUM> prior to unsheathing of the braided wire mesh <NUM>. It will thus be understood that unsheathing of the valve <NUM> occurs initially within the ventricle <NUM> by the hooks <NUM>, and subsequently in the atrium <NUM> by the braided wire mesh <NUM>. In accordance with the present invention however, these unsheathing steps are reversed such that initial unsheathing of the braided wire mesh <NUM> occurs in the atrium <NUM> before subsequent unsheathing of the hooks <NUM> through the annulus <NUM> to the ventricle <NUM>.

Unsheathing of the valve <NUM> in the manner described above is effected by altering the manner in which the valve <NUM> is loaded within the catheter <NUM> or, as will be described below, an alternative delivery device such as a capsule specifically configured to retain the valve <NUM> in a collapsed condition. More specifically, the valve <NUM> is loaded within the catheter <NUM> in a reversed and partially inverted orientation compared to the manner described above. Reference is made to <FIG> where features common to those described with reference to <FIG> are identified with like reference numerals. The catheter <NUM> includes a distal aperture <NUM> through which the valve <NUM> is inserted prior to introduction of the catheter <NUM> into a patient. The valve <NUM> is delivered through the distal aperture <NUM> of the catheter <NUM> when the valve <NUM> is unsheathed in the annulus of a mitral valve of a human heart.

As before, the catheter wall <NUM> exerts radial pressure on the valve <NUM> in order maintain both the inner frame <NUM> and braided wire mesh <NUM> and thereby the flange <NUM> in the radially compressed condition. It will however be appreciated that the orientation of the valve <NUM> shown in <FIG> differs from that shown in <FIG>. In <FIG>, the valve <NUM> is positioned within the catheter <NUM> such that the tops <NUM> of the hooks <NUM> are proximal to the distal aperture <NUM> of the catheter <NUM>. The hooks <NUM> extend both away from the inner frame <NUM> and flange <NUM> in the direction of the distal aperture <NUM> of the catheter.

Referring now to <FIG>, the valve <NUM> is positioned within the catheter <NUM> with the circumferential flange inverted such that the braided wire mesh <NUM> and flange <NUM> overlie the hooks <NUM>. The hooks <NUM> are thus held radially inwardly of the flange <NUM>. The portion of the valve <NUM> that is proximal to the distal aperture <NUM> of the catheter <NUM> is the portion of the flange <NUM> that defines the outer circumferential periphery <NUM> of the flange <NUM>.

It will be appreciated that the orientation of the radially compressed valve <NUM> within the catheter <NUM> prevents close interaction of the leaflets <NUM> with the frame <NUM>. The possibility of the leaflets <NUM> this being damaged or otherwise detrimentally affected by frame <NUM> is reduced.

The circumferential flange <NUM> is considered inverted as its orientation relative to inner frame <NUM> when the prosthetic heart valve <NUM> is in the radially compressed condition is opposite to that exhibited when the prosthetic heart valve <NUM> is in the radially uncompressed condition. More specifically, a circumferential surface of the flange <NUM> which faces inwardly and towards the inner frame <NUM> when the prosthetic heart valve <NUM> is in the radially uncompressed condition is repositioned so as to face radially outwardly and away from the inner frame <NUM> when the prosthetic heart valve <NUM> is in the radially compressed condition. Similarly, a circumferential surface of the flange <NUM> which faces outwardly and away from the inner frame <NUM> when the prosthetic heart valve <NUM> is in the radially uncompressed condition is repositioned so as to face radially inwardly and towards the inner frame <NUM> when the prosthetic heart valve is in the radially compressed condition.

The manner in which the valve <NUM> is loaded into the catheter <NUM> is shown in <FIG>. <FIG> shows the valve <NUM> in the radially uncompressed condition positioned over a tapered conduit <NUM>. The tapered conduit <NUM> is utilised to transition the valve <NUM> from the radially uncompressed condition to the collapsed condition within the catheter <NUM>. The tapered conduit <NUM> has a first substantially circular opening or aperture <NUM>, a second substantially circular opening or aperture <NUM> and a tapered lumen <NUM> extending there between. The first opening <NUM> has a greater diameter than the second opening <NUM>. The diameter of the first opening <NUM> is greater than the uncompressed diameter of the inner frame <NUM> but less than the diameter of the flange <NUM>. The diameter of the second opening <NUM> is approximately the same as the distal aperture <NUM> of the catheter <NUM>. It will be understood that the taper of the lumen <NUM> between the openings <NUM>,<NUM> causes compression of the valve <NUM> as the valve <NUM> is drawn through the conduit from the first opening <NUM> to the second opening <NUM>.

Referring again to <FIG>, the valve <NUM> is positioned over the first opening of tapered conduit <NUM> such that the inner frame <NUM> is received through the first opening <NUM> and into the lumen <NUM>, and the braided wire mesh <NUM> and flange <NUM> extend around first opening <NUM>. The tapered conduit <NUM> is provided adjacent the catheter such that the second opening of the tapered conduit <NUM> faces the distal opening <NUM> of the catheter <NUM>. Removably attached to the inner frame <NUM>, and extending through the tapered conduit <NUM>, are traction wires <NUM> which are used to draw the valve <NUM> through the conduit <NUM>. It will be understood that other methods may be employed to draw the valve <NUM> through the conduit <NUM>. These may include, but not be limited to, manual manipulation, the use of a plunger tool, or the use of an iris crimper. The hooks <NUM> of the valve <NUM> can be seen overlying the exterior of the wire mesh <NUM>.

<FIG> shows the position of the valve <NUM> after initial longitudinal movement of the inner frame <NUM> into the lumen <NUM> of the tapered conduit <NUM>. The hooks <NUM> can still be seen to the exterior of the tapered conduit <NUM> and overlying the exterior of the wire mesh <NUM>.

<FIG> shows the position of the valve <NUM> after further longitudinal movement of the inner frame <NUM> into lumen <NUM> of the tapered conduit <NUM>. Radial compression of the inner frame <NUM> by the taper of the lumen <NUM> has commenced and the wire mesh <NUM> has begun to be drawn into the lumen <NUM>. It will be noted that the force applied to the wire mesh <NUM> and flange <NUM> by the first opening <NUM> has caused inversion of the flange <NUM> such that the wire mesh <NUM> now overlies the hooks <NUM> as opposed to the hooks <NUM> overlying the wire mesh <NUM>. It will be understood that continued longitudinal movement of the valve <NUM> through tapered lumen <NUM> causes radial compression of the inner frame <NUM> and wire mesh <NUM> to a diameter equal to that of the second aperture <NUM> of the tapered conduit <NUM>.

As noted above, the tapered conduit <NUM> is positioned adjacent the catheter <NUM>, and the collapsed valve <NUM> can be thus be loaded into the catheter <NUM> through the distal aperture thereof by continued longitudinal movement. This is shown in <FIG>.

The valve <NUM> may be loaded into the catheter <NUM> shortly prior to the scheduled surgical procedure to implant the valve <NUM> into a patient. As such, the loading of the valve <NUM> into the catheter <NUM> may be undertaken by a surgeon or a surgical practitioner during preparation for the implantation procedure.

In an alternative embodiment, the valve <NUM> may be supplied to a surgeon or surgical practitioner pre-loaded into a delivery capsule, which itself is then positioned in the catheter <NUM>. In such an embodiment the delivery capsule may be provided with removable endcaps and contain a sterile liquid medium which surrounds the valve <NUM>. The delivery capsule may further be provided with flushing ports to enable the sterile liquid medium to be removed from the delivery capsule. The manner in which the valve <NUM> is loaded into a delivery capsule is the same as that described above for the loading of a valve <NUM> into a catheter <NUM>. The delivery capsule may be formed integrally with a catheter <NUM>. Alternatively, the delivery capsule may be configured so as to be mountable or otherwise attachable to a catheter <NUM>.

<FIG> show the manner in which the valve <NUM> is unsheathed from the catheter <NUM>. Unsheathing of the valve <NUM> is achieved by longitudinally advancing the collapsed valve <NUM> through the lumen of the catheter <NUM> and out of the distal aperture <NUM> of the catheter <NUM>.

<FIG> shows the initial unsheathing of the wire mesh <NUM> through the distal aperture <NUM> of the catheter <NUM>. Free from the constraints of the catheter wall <NUM>, the mesh <NUM> is able to radially expand as shown. Such radial expansion is driven by the inherent resilience of the mesh <NUM> and/or shape memory attributes of the materials utilised for the mesh <NUM> and inner frame <NUM>. It will be noted however that the flange <NUM> is still in the inverted state, and that the outer circumferential periphery <NUM> of the flange <NUM> is projects distally of the distal aperture <NUM> of the catheter <NUM>.

Delivery of the valve <NUM> requires the circumferential periphery <NUM> of the flange <NUM> to engage an annulus <NUM> separating the left atrium <NUM> and the left ventricle <NUM>. This engagement is illustrated in <FIG> whereby spaced apart fingers simulate the annulus <NUM>. It will be understood that the distal projection of the inverted flange <NUM> from the distal aperture <NUM> of the catheter <NUM> means that the catheter <NUM> can be located fully within the atrium <NUM>, and thus does not need to be positioned through the annulus <NUM> and into the ventricle <NUM> in order to effect unsheathing of the valve <NUM>. Supra-annular unsheathing of the valve <NUM> may thus be effected.

<FIG> show the continued unsheathing of the valve <NUM> as the result of continued longitudinal advancement of the collapsed valve <NUM> through the lumen of the catheter <NUM> and out of the distal aperture <NUM> of the catheter <NUM>. This includes the reversion of the flange <NUM> to its original non-inverted state (also indicated by arrows <NUM> on <FIG>), and the re-positioning of the hooks <NUM> to the exterior of the braided wire mesh <NUM>.

The manner in which the valve <NUM> may be unsheathed from a delivery capsule corresponds to that described above with reference to the unsheathing of the valve <NUM> from a catheter <NUM>.

Claim 1:
A method of loading a prosthetic heart valve (<NUM>) into a delivery device, the prosthetic heart valve (<NUM>) including:
an inner frame (<NUM>) having a tubular shape; and
a braided wire mesh (<NUM>) arranged outside of the inner frame (<NUM>) and defining a circumferential flange (<NUM>) around the inner frame (<NUM>);
the method comprising the steps of:
providing a delivery device having a lumen defined by a wall and a distal aperture (<NUM>) at a distal end thereof, the lumen having a diameter that is less than that of the inner frame (<NUM>) and braided wire mesh (<NUM>);
providing the prosthetic heart valve (<NUM>) in a radially uncompressed condition;
positioning the prosthetic heart valve (<NUM>) such that the inner frame (<NUM>) is received through the distal aperture (<NUM>) and into the lumen;
moving the prosthetic heart valve (<NUM>) fully into the lumen such that the inner frame (<NUM>) and braided wire mesh (<NUM>) are radially compressed; wherein the step of moving the braided wire mesh (<NUM>) into the lumen of the delivery device includes inverting the circumferential flange (<NUM>).