Patent Description:
The invention has been developed with particular regard, though in a non-limiting manner, for a device for use during a procedure for implanting a heart prosthesis for replacing the physiological function of a malfunctioning heart valve and in particular a heart prosthesis for an atrio-ventricular heart valve.

Heart valves are complex and delicate organs which govern the correct function of the human heart. The main objective thereof is to make the blood flow inside the cardiac cavities unidirectional, being essential both in the filling phase of the cavity, the diastolic phase, and in the discharge phase of the blood, the systolic phase.

In order to optimize the efficiency of the pumping action of the blood, the heart is structured in two different compartments, right and left, respectively, each of which is in turn subdivided into two chambers, the atrium and ventricle, respectively. The right compartment of the heart, which is composed by the right atrium and ventricle, returns the blood from the peripheral circulation and directs it towards the pulmonary circulation for oxygenation thereof. The left compartment, which is similarly subdivided into left atrium and ventricle, supplies the peripheral vascularization, returning the oxygenated blood from pulmonary circulation and pumping it towards the systemic circulation.

In order to make the blood flow unidirectional inside the heart, a valve is positioned at the outlet of each chamber. The valves which are positioned at the outlet of the atria are the atrio-ventricular valves because they connect the atrial chamber to the ventricular chamber of each side of the heart. At the right side of the heart, this valve is also referred to as the tricuspid valve, at the left side it is usually indicated as the mitral valve. Finally, the valve which is positioned at the outlet from the right ventricle is called the pulmonary valve while the valve at the outlet from the left ventricle is called the aortic valve.

Pathologies which affect the function of a heart valve are among the most serious in the cardiovascular field. Among these, the insufficiency of the mitral valve, that is to say, the incapacity thereof to close completely, is a valve pathology which is highly impairing because it reduces the efficiency of the pumping action at the left side of the heart, which is responsible for blood circulation for the entire body.

In the current prior art, the standard therapy for treating severe valve malfunctions is the replacement of the valve with an implantable prosthesis. In other cases, mainly in the case of malfunctions of the mitral valve, there is provision for the repair thereof. In both cases, it is provided via an open-heart surgical procedure which affords direct access to the malfunctioning valve. This procedure requires the temporary arrest of the heart and the creation, by means of suitable pumps and oxygen exchangers, of an extracorporeal artificial blood circulation. Notwithstanding the refinement of the techniques for managing the cardiac arrest and improving the extracorporeal circulation systems, the therapy in open heart conditions presents risks as a result of the invasive nature thereof and the duration of the procedure. In fact, the implantable prostheses, both for repairs and for replacements, commonly used during the conventional surgery usually require a long operation for fixing at the location of the implantation by means of specific suture techniques. In some cases, it is not even possible to intervene surgically as a result of the general conditions of the patient, for example, due to advanced age or the presence of concomitant pathologies.

In order to overcome these limitations, there have recently been developed procedures with interventions of reduced invasiveness, so-called transcatheter procedures. To this end, radially collapsible prostheses which can self-anchor at the implantation site are used. The prostheses can be implanted by means of catheters which are capable of navigating inside the vascular system and releasing the heart prosthesis by reaching the implantation site from a remote access created, for example, in a peripheral vessel, such as a femoral vein or artery. The valve malfunctions can thus be corrected with a beating heart and with limited use of surgical practices. In the current state, transcatheter techniques are clinical standard of care only for treating the aortic valve.

The situation is different with regard to the treatment of malfunctions of the atrio-ventricular valves, in particular the treatment of mitral insufficiency. The complex anatomical configuration of the valve and of the structures which surround it, the variability of the pathologies, also very different from each other, which affect the valve directly or indirectly, make extremely difficult to comply with the requirements for a reliable and effective implantation in a mitral valve via the transcatheter route.

In the variety of single designs developed, the main technologies developed for transcatheter prostheses for atrio-ventricular valves provide for apical access to the heart. The procedure requires a thoracic incision in order to expose the apex of the left ventricle. Subsequently, the cardiac apex is punctured in order to be able to insert an apical port. Via the apical port, the catheters necessary to complete the procedure are inserted successively.

A problem of this approach is that it brings about damage to the heart in a rather delicate portion, such as the apex, with consequences that can be detrimental to the patient, such as bleeding, aneurisms, etc. <CIT> discloses a guide wire introduction device for positioning a guide wire around a heart valve.

An object of the invention is to solve the problems of the prior art and in particular to provide a device for use in a procedure for implanting a heart prosthesis which is transcatheter and which does not damage the apex of the heart. Another object is to provide a device for use in a procedure which is even safer for the patient. In particular, an object is to provide a guidewire introducer device and a device for implanting a heart prosthesis which are reliable during use and safe in order to allow such a procedure to be carried out. Another object is to provide a procedure for assembling a heart prosthesis using such a device for implantation.

The disclosure relates to a guidewire introducer device and a device for implanting a heart prosthesis which are developed specifically for allowing a transcatheter implantation procedure with transseptal access, as developed by the Applicant. With transseptal access it is intended to be understood an access to the mitral valve which, starting from a peripheral femoral vein, navigates in the inferior vena cava up to the right atrium and finally arrives at the left atrium through an aperture which is created, with interventional methods, in the septum between the two atria. The left atrium affords anterograde access to the mitral valve to be treated. In this manner, damage, that is to say perforation, of the left ventricle which is associated with the transapical procedure, that provides access to the mitral valve from the ventricular side, that is to say retrograde, is prevented.

According to a first aspect, there is described a guidewire introducer device for positioning at least one guidewire around a heart valve. The device may be capable of deploying guidewires through transseptal access. The device may comprise a first catheter which may be provided with at least one distal deflection system. The device may comprise a second catheter which may be inserted inside the first catheter. The second catheter may comprise a lumen which is suitable for having a guidewire sliding therein. The second catheter may be provided with a distal deflection system for deflecting the end thereof, preferably through an angle greater than <NUM>° in order to allow the zone immediately under the leaflets of the native valve to be best reached. The device may comprise a third catheter. The third catheter may be inserted inside the first catheter. The third catheter may have therein a device for capturing the guidwires. The third catheter may be provided with a distal deflection system. The deflection system of the second catheter may comprise a wire. According to another aspect, there is described a guidewire introducer device for deploying at least two guidewires around a heart valve. The second catheter may comprise two lumens which are suitable for having guidewires sliding therein. The two lumens may terminate so as to face in substantially mutually opposite directions.

According to an advantageous aspect, a guidewire introducer device comprises a second catheter. The guidewire introducer device is provided with a radiopaque and/or echo-opaque element. The radiopaque/echo-opaque element may be positioned on a distal tip of the second catheter, preferably embedded therein.

According to another aspect, a guidewire introducer device may comprise a first catheter with a single lumen.

According to another aspect, there is described a procedure for positioning at least one guidewire around a heart valve; the procedure may comprise the step of providing access for a first catheter through a vein, preferably the femoral vein. The first catheter may be introduced inside the right atrium, through the inferior vena cava IVC. There may be produced a puncture in the septum between the two atria in order to access the left atrium. The procedure may comprise the step of inserting a guidewire introducer device in the left ventricle, passing though the mitral valve, and deploying one or more guidewires around the native valve.

According to a preferred aspect, there is described a procedure for positioning at least one guidewire around a heart valve, the procedure comprising the steps of:.

According to another aspect, there is described a device for implanting a heart prosthesis. The heart prosthesis may comprise a central body and a containment portion. The containment portion may be subdivided into one or more sub-components. The device for implanting a heart prosthesis may comprise a release device for the central body. The release device may be capable of being inserted into a catheter. The device for implanting a heart prosthesis may comprise a device for assisting the connection operation between the central body and the sub-components of the containment portion. The device for assisting the connection operation between the central body and the sub-components of the containment portion may comprise an assembly of catheters. There may be at least two catheters for each sub-component of the containment portion. The catheters may be joined to each other via a portion thereof and may each have at least one free end. The catheters may be grouped together in the same sheath. The sheath may group together the catheters along a portion thereof. The sheath may leave free at least one end for each catheter. The sheath may further comprise an additional lumen for a guidewire, preferably a central one. Advantageously, the catheters which constitute the assembly of catheters may be steadily joined to each other.

According to another aspect, a device for assisting the connection operation between the central body and the sub-components of the containment portion may comprise an assembly of catheters which are incompressible in a longitudinal direction. In this manner, during use, they form an incompressible abutment channel for a guidewire. Preferably, the catheters which constitute the assembly of catheters may be flexible.

According to another aspect, there is described a procedure for assembling a heart prosthesis. The heart prosthesis may comprise a central body and a containment portion. The containment portion may be subdivided into one or more sub-components. The procedure described may comprise the step of inserting a guidewire into each sub-component of the containment portion. It may comprise the step of sliding the sub-components in such a manner that both the ends of the guidewire are outside the sub-component itself. The procedure may comprise the step of inserting, for each sub-component of the containment portion, each end of the guidewire in a corresponding connecting element, for the connection of the central body and the containment portion. The procedure may comprise the step of inserting each end of the guidewire into a corresponding catheter of the assembly of catheters. It may comprise the step of drawing the ends of each guidewire in order to connect the central body and the sub-components of the containment portion.

According to another aspect, there is also described a procedure for implanting a heart prosthesis. The heart prosthesis may comprise a central body and a containment portion, which is sub-divided into one or more sub-components. The procedure may comprise the step of affording access for a first catheter through a vein. Preferably, the access may be afforded in the femoral vein. The procedure may comprise the step of inserting the first catheter through the inferior vena cava IVC. The first catheter may be inserted up to inside the right atrium. There may be created a puncture in the septum between the two atria. Through this puncture, it is possible to access the left atrium. The procedure may comprise the step of providing one or more guidewires around the native valve; this operation may be carried out by means of a guidewire introducer device. It is possible to insert the sub-components of the containment portion. The procedure may comprise the step of inserting a device for implanting a heart prosthesis. It is then possible to connect the central body to the sub-components <NUM> of the containment portion <NUM>. The release in position of the central body may be brought about by pushing the central body out of the device for implantation.

According to another aspect, the procedure for implanting a heart prosthesis provides for the step of inserting each sub-component into the heart by guiding it with at least one guidewire which is arranged around the native valve, preferably sliding each sub-component over the at least one guidewire (over the wire).

According to another aspect, the procedure for implanting a heart prosthesis may provide for using a device for implanting a heart prosthesis comprising a device for assisting the operation of connecting the central body and the sub-components of the containment portion which may comprise an assembly of catheters; the procedure may comprise the steps of inserting each end of the guidewire into a corresponding connecting element for the connection of the central body and the containment portion and inserting each end of the guidewire into a corresponding catheter of the assembly of catheters, in the free end thereof. The procedure may further comprise the step of acting on the ends of the guidewire in order to establish the connection between the central body and the sub-component of the containment portion.

According to another aspect, there is described a procedure for implanting a heart prosthesis comprising a central body for prosthetic leaflets and a containment portion which is subdivided into one or more sub-components, the procedure comprising the steps of:.

There is further described a procedure for implanting a heart prosthesis, in which each sub-component is inserted by sliding it over one of the guidewires which are arranged around the native valve.

Advantageously, a procedure for implanting a heart prosthesis uses a device for implanting a heart prosthesis with all or some of the above-described features; according to the procedure, after inserting the sub-components, for each sub-component of the containment portion there are carried out the steps of:.

The solution according to one or more embodiments of the invention, as well as additional characteristics and the relative advantages, will be better understood with reference to the following detailed description which is given purely by way of non-limiting example and which is intended to be read with the appended Figures, in which for simplicity corresponding elements are referred to with identical or similar reference numerals and the explanation thereof is not repeated. In this regard, it may be expressly understood that the Figures are not necessarily to scale, with some details which may be exaggerated and/or simplified and that, unless indicated otherwise, they are simply used to conceptually illustrate the structures and the procedures described.

Now with reference to the drawings, in <FIG> there is described an implantable heart prosthesis <NUM> which is used to replace the functionality of an atrio-ventricular valve.

The heart prosthesis <NUM> comprises a prosthetic structure <NUM> for support and interfacing with the native valve and by a group of flexible prosthetic leaflets <NUM> which are fixed therein. The prosthetic structure <NUM> comprises in particular:.

The prosthetic structure <NUM>, as for each of the elements thereof, is configured so as to be collapsible without any consequence for the safety and the functionality of the heart prosthesis. Therefore, it is possible to temporarily reduce the radial dimensions of the prosthesis in order to allow the introduction thereof inside the cardiac cavities through access ports which have a reduced aperture and which are compatible with the techniques of minimal invasive surgery, and in particular with the techniques of transcatheter positioning and heart prosthesis implantation according to the present disclosure.

In other words, it is possible to insert the heart prosthesis <NUM> inside a catheter with a small radial profile, which is capable of conveying the prosthesis inside the heart cavity, near the implantation site, through a minimal invasive access, and there to carry out the deployment and the implantation thereof, functionally replacing the native valve.

There are described in detail herein below the different portions, into which the prosthetic structure <NUM> is divided. The central body <NUM> is the portion of the prosthetic structure <NUM> which delimits the conduit for the passage of blood through the device. There are fixed inside the central body <NUM> the flexible prosthetic leaflets <NUM> which make the blood flow unidirectional inside the conduit, as known, for example, from the <CIT> by the same Applicant.

The central body <NUM> is a radially collapsible resilient structure which tends, as a result of resilient return, also to expand to a diameter greater than the maximum diameter which maintains coaptation, that is to say, the contact, between the free edges of the closed prosthetic leaflets <NUM>.

The containment portion <NUM> is the portion of the prosthetic structure which counteracts and limits the free expansion of the central body <NUM>, preventing it from exceeding the maximum diameter which is compatible with the preservation of coaptation between the prosthetic leaflets <NUM>. The containment portion <NUM> has a substantially annular geometry and is longitudinally inextensible, that is to say, it does not modify significantly the peripheral extent thereof even when the central body <NUM> expands inside it while applying a radial force outward.

The containment portion <NUM> is preferably subdivided into two sub-components <NUM> which are separated from each other, substantially in the form of an arc; for simplicity, the two sub-components will be indicated below by the term "arcs". Each arc <NUM> can be selectively engaged with the connecting elements <NUM>, with which it is steadily joined in the final implantation configuration.

Each end <NUM> of each sub-component <NUM> is equipped with an engagement portion <NUM>, preferably capable of assuming orientations outside the annular plane. In the embodiment depicted, the engagement portion <NUM> is orientated substantially perpendicularly to the plane of the annulus. In turn, the connecting elements <NUM> are equipped with pins <NUM> which are suitable for being received in axial holes <NUM> which are present in the engagement portions <NUM>. A pair of pins <NUM> is present on each of the two connecting elements <NUM>, arranged substantially in angular positions which are diametrically opposed with respect to the central body <NUM>. These pins <NUM>, as well as the engagement portions <NUM> which are present at the ends of the arcs <NUM> of the containment portion <NUM>, can be provided with barbs or lips or other surface discontinuities which are intended to create mechanical interference between the portions and/or to increase the friction in the pin/hole connection, improving the stability of the connection between the sub-components <NUM> of the containment portion <NUM> and the connecting elements <NUM>. The pins <NUM> are orientated in a coherent manner relative to the orientation of the engagement portions <NUM> which are present on the sub-components <NUM> of the containment portion <NUM>, so that the pin/hole connection maintains the containment portion in a geometrically consistent plane with the annulus of the native valve. Furthermore, the pins <NUM> are pierced axially in order to allow the passage of a guidewire, as better described below.

It is evident that the pin/hole connection mechanism could instead comprise a pin at the end of the sub-components <NUM> and a cylindrical hole in the connecting elements <NUM>. More generally, the pin/hole connection has a purely exemplary purpose, without any limiting intention of the generality of the solution.

Naturally, the prosthesis may also comprise a different number of sub-components <NUM>. For example, it may comprise a single sub-component and therefore be formed in the manner of an open ring. The version described with two sub-components <NUM> is the preferred one, however, because it allows the use of two guidewires which, as a result of the introducing device for guidewires described below, are easier to position correctly than a single guidewire which could remain entangled in the chordae tendineae. However, a third sub-component does not simplify the positioning operations and therefore is substantially unnecessary, but should not be excluded.

In use, the leaflets of the native valve remain entrapped inside the coupling between the central body <NUM> and the containment portion <NUM>. Furthermore, the containment portion <NUM> also has the function of stabilizing the native valve annulus, preventing the radial force applied by the central body <NUM>, while being necessary to ensure effective anchoring of the prosthesis, from being transferred to the surrounding anatomical structure which is usually affected by degenerative and dilating processes which are associated with the pathology which makes the atrio-ventricular valve malfunction.

For clarity reasons, in the drawings of <FIG>, as for in the Figures which follow, the external diameter of the central body <NUM> is illustrated having dimensions less than the internal dimensions of the containment portion <NUM>. In other words, the Figures show these two components of the prosthetic structure <NUM> not in contact with each other in the configuration of full expansion. In reality, it is possible to have over-dimensioning of the central body <NUM> with respect to the dimensions of the containment portion <NUM>. In this case, there is an interference between the two portions of the prosthetic structure <NUM> and effectively the central body <NUM> applies a radial pressure to the containment portion <NUM> when the latter carries out its constraining action with respect to the expansion, independently of the thickness of the tissue which remains captured in between the two portions of the prosthetic structure <NUM>. This radial pressure increases the stability of the anchorage to the native valve leaflets.

There will now be described a preferred procedure for implantation of the heart prosthesis <NUM> described above.

Initially, there is afforded access through the femoral vein or the iliac vein. Where possible, the access from the femoral vein is preferred because it is significantly simpler and more direct. In particular, it doesn't require an invasive surgical procedure. An introducer catheter may be used with the main objective of protecting the femoral vein which has a small calibre.

The introducer catheter, when present, is positioned through the femoral vein in order to create the access to a vessel having a larger diameter. There is then inserted a main catheter <NUM> which slides inside the introducer catheter, when provided, through the inferior vena cava IVC up to the right atrium, as can be seen in <FIG>.

The main catheter <NUM> is provided with a distal deflection system so that the end <NUM> thereof can be bent by the operator in the direction of the left atrium. A puncture in the septum S between the two atria is then performed, allowing access to the left atrium. Inside the main catheter <NUM>, a guidewire introducer device <NUM> is inserted.

As mentioned above, it is not mandatory to provide an introducer catheter but instead there may be used directly a main catheter <NUM> which gains access to the right atrium through the inferior vena cava. Furthermore, the main catheter may also be inserted up to a location inside the left atrium; it thereby allows the insertion of the guidewire introducer device <NUM> directly in the left atrium.

The guidewire introducer device <NUM> is a device the function of which is to allow the deployment around the leaflets of the native mitral valve V of guidewires which are necessary for the subsequent positioning of the heart prosthesis <NUM>.

The guidewire introducer device <NUM> comprises a first catheter <NUM>, inside which a second catheter <NUM> and a third catheter <NUM> slide. The first catheter <NUM> is a single-lumen catheter. It is provided with a distal deflection system so that the end <NUM> thereof can be orientated by the operator in the direction of the mitral valve V.

The second catheter <NUM>, which can better be seen in the detailed <FIG>, comprises two lumens <NUM> and <NUM> which are suitable for having guidewires sliding therein. The two lumens are arranged parallel with each other and beside each other over a greater portion of the second catheter <NUM>. In the end <NUM> of the second catheter <NUM>, the two lumens curve through an angle of approximately <NUM>° in substantially opposite directions. The two lumens <NUM> and <NUM> therefore terminate not at a distal tip <NUM> of the catheter <NUM>, but instead at the side thereof in diametrically opposed positions in respective holes <NUM> and <NUM>. In other words, two guidewires inserted in the lumens <NUM> and <NUM> exit from the second catheter <NUM> oriented in diametrically opposed directions.

The second catheter <NUM> further comprises a deflection system. The deflection system according to the exemplary embodiment depicted comprises a wire <NUM>. The wire <NUM> is fixed to the end <NUM> of the catheter, runs externally from the catheter over a short portion and then inside the catheter. The operator may pull the wire <NUM> in order to establish a curvature, which can be very pronounced, for the second catheter <NUM>, as can clearly be seen in <FIG>. The curvature is greater than <NUM>°. However, it is not impossible to use other deflection systems. For example, inside the second catheter there may be incorporated a segment of a shape-memory material so that it can be inserted in a stretched state in the first catheter <NUM> and recovers the correct curvature when it is pushed out of the first catheter <NUM>. An example of such a configuration is shown in <FIG>, in which a wire <NUM> of shape-memory material, for example, of titanium nickel alloy (Nitinol) is incorporated inside the second catheter <NUM>.

There is provided at the distal tip <NUM> a segment <NUM> of radiopaque or echo-opaque material. The segment <NUM> is embedded inside the distal tip <NUM> which is preferably rounded in order to prevent accidental lesions.

The third catheter <NUM>, as better described below, is also inserted inside the first catheter <NUM> and receives therein a guidewire capturing device <NUM> (a snaring device), as better described below. It may be noted that the guidewire capturing device which is depicted, comprising different collapsible rings or loops grouped together, is one of the many possible capturing devices which can be used that has been found to be particularly effective for the specific application. However, different capturing devices are not excluded, for example, having a single loop or a different number from the one of the device depicted.

Now turning to the procedure for implanting the heart prosthesis, the guidewire introducer device <NUM> which has been inserted inside the main catheter <NUM> is advanced inside the left atrium (<FIG>), through the septum S. It may be noted that the end <NUM> of the main catheter <NUM> may be located in the right atrium, as in the Figure, or in the left atrium. The end <NUM> of the first catheter <NUM> of the guidewire introducer device <NUM> is bent so that it points towards the valve V, therefore towards the bottom in <FIG>.

The second catheter <NUM> of the guidewire introducer device <NUM> is made to slide inside the first catheter <NUM> of the guidewire introducer device <NUM> (<FIG>); the end <NUM> exits and takes on a pronounced curvature which is directed in the opposite direction to the curvature of the end <NUM> of the first catheter <NUM>. The second catheter <NUM> is in fact bent upwards in <FIG>.

The guidewire introducer device <NUM> is advanced further (<FIG>) inside the main catheter <NUM> and the second catheter <NUM> is pushed into the left ventricle, through the valve V.

Once the second catheter <NUM> of the guidewire introducer device <NUM> is inside the left ventricle, it is slightly retracted so that the distal tip <NUM> thereof is positioned behind the posterior leaflet of the native valve. In particular, the distal tip <NUM> is preferably positioned behind the central segment (scallop) which is normally designated as P2. To this end, the presence of the segment <NUM> of radiopaque material at the distal tip <NUM> is particularly advantageous. In case of doubts concerning the exact positioning or the orientation of the end <NUM> of the catheter, it is in fact possible to verify it directly with an ultrasound probe or by means of fluoroscopy. The segment <NUM> of radiopaque material is to be oriented in a direction tangent to the edge of the valve.

<FIG> shows a detailed schematic view of the left ventricle, in which the native mitral valve V is clearly visible, with the two bundles of chordae tendineae T, as well as the aortic valve A. The end <NUM> of the second catheter <NUM> of the guidewire introducer device <NUM> is depicted in the correctly positioned state behind the posterior leaflet of the native valve V. It may be noted that the catheter <NUM> does not cross the bundles of chordae tendineae.

Now with reference to <FIG>, the third catheter <NUM>, with the guidewire capturing device <NUM> therein, is slided inside the first catheter <NUM> until it is introduced inside the left ventricle. The second catheter also has, near the end <NUM> thereof, a deflection system <NUM>. This deflection system may be generally identical to the wire <NUM> described above with reference to the second catheter <NUM>. According to a preferred variant, however, it is made for constructional simplicity with a wire which slides inside the wall of the catheter; a flexible metal structure with a rigid backbone embedded in the thickness of the catheter produces the effect of the curvature. Other known mechanisms in the prior art should not be excluded, however. Furthermore, the guidewire capturing device <NUM> is inserted in a covering sheath <NUM>.

The third catheter <NUM> is orientated with the end <NUM> curved in an opposite direction with respect to the direction in which the end <NUM> of the second catheter is curved, therefore in the direction of the aortic valve. The guidewire capturing device <NUM> is pushed out of the respective third catheter <NUM> and out of the sheath <NUM> until it is positioned in the LVOT (left ventricular outflow tract), that is to say in front of the aortic valve.

By maintaining the guidewire capturing device <NUM> in this position, a first guidewire <NUM> is inserted in the first lumen <NUM> of the second catheter of the guidewire introducer device <NUM>. The end <NUM> of the guidewire <NUM> is pushed (<FIG>) into the ventricle by the operator. As a result of the effect of the precise positioning of the distal tip <NUM> of the second catheter <NUM>, of the lateral position of the outlet <NUM> of the lumen <NUM>, of the heart configuration, and of the blood stream that during systole is naturally directed towards the aortic valve A, the end <NUM> of the guidewire <NUM> is driven around the valve and in the direction of the LVOT. Once the LVOT has been reached, it is captured by the guidewire capturing device <NUM> which has already been positioned beforehand. Subsequently, the retrieval of the end <NUM> of the guidewire <NUM> is carried out, by withdrawing the third catheter <NUM>.

Alternatively, it is also possible to position the guidewire capturing device <NUM> inside the aorta, that is to say beyond the aortic valve A. The guidewire will be pushed into the aorta by the blood flow and the capture operation may therefore be carried out.

Once the end <NUM> of the guidewire <NUM> has been captured, the guidewire <NUM> forms a half-loop around the valve V (<FIG>).

In a generally symmetrical manner, it is carried out the formation of a similar half-loop around the valve V with a second guidewire <NUM> that is inserted into the second lumen <NUM> of the second catheter <NUM>. In this manner, the valve V is completely surrounded by the two guidewires <NUM> and <NUM>, which are correctly positioned. To this end, it is possible to use the same guidewire capturing device <NUM> which is used to capture the first wire or, preferably, another guidewire capturing device <NUM> which is also received in the third catheter <NUM>. In this case, the third catheter <NUM> preferably has a double lumen.

Naturally, it is also possible to use a guidewire positioning device which is similar to the one described above in detail in order to position a single guidewire which carries out the complete loop around the native valve. In this case, however, the guidewire positioning procedure becomes more complex: although there are fewer steps necessary (it is not necessary to repeat the steps for the second wire), it is not easy to orientate a guidewire in a sufficiently precise manner around the entire valve because there is the risk of remaining entangled in the chordae tendineae. Indeed, using two guidewires allows to leverage the geometry of the heart and the natural blood flow to facilitate the operations and to minimize the risk of errors which can have serious consequences for the patient if not identified and corrected immediately.

Now with reference to <FIG>, the first catheter <NUM> and the second catheter <NUM> are preferably left in position in this step in order to facilitate the insertion into the ventricle of the two arcs <NUM> which constitute the containment portion <NUM> of the heart prosthesis <NUM>. The two arcs are inserted over the wire, that is to say by sliding on the guidewires. In other words, there is used a longitudinal channel which extends through one of the two arcs in order to insert therein the end <NUM> of the guidewire <NUM> which has just been recovered; similarly, the end of the guidewire <NUM> is inserted into the longitudinal channel which extends through the other arc. Both the arcs <NUM> are then pushed until they are out of the first catheter <NUM> and inside the heart. The arcs <NUM> are pushed until being in contact with the tip <NUM> of the second catheter <NUM>. At this point, the first catheter <NUM> and the second catheter <NUM> can be removed.

It is preferable to leave the main catheter <NUM> in position and to use it for subsequently introducing therein a device <NUM> for implanting a heart prosthesis, in which a central body <NUM> is inserted. The removal of the main catheter <NUM> or the replacement thereof with another catheter is not excluded in any case.

The device <NUM> for implanting a heart prosthesis, the details of which can be seen in <FIG>, comprises a catheter <NUM>, through which there are inserted all the other elements as well as the central body <NUM> of the prosthesis.

The device for implanting a heart prosthesis further comprises a release device <NUM> for the central body <NUM> of the prosthesis. The release device <NUM> is suitable for being inserted into a catheter in order to advance therein the central body <NUM> of the prosthesis. The device <NUM> for implanting a heart prosthesis further comprises a device <NUM> for assisting the connection operation between the central body <NUM> and the sub-components of the containment portion <NUM>. This assistance device <NUM> comprises an assembly of catheters <NUM>, of which there are at least two for each arc of the containment portion that are grouped together in the same sheath <NUM> which partially covers the catheters and leaves at least one free end <NUM> for each catheter.

In the preferred case depicted, in which the prosthesis comprises two arcs <NUM>, the assistance device <NUM> comprises four catheters <NUM>. Naturally, if the prosthesis were to comprise a single sub-component of the containment portion <NUM>, two catheters would be sufficient. If, however, the prosthesis comprises three or more sub-components, six or more catheters will be provided.

The catheters <NUM> are incompressible in the longitudinal direction and are flexible. Furthermore, they are fixed inside the sheath <NUM> so that they do not slide with respect to each other. Preferably, the sheath <NUM> further comprises a free longitudinal lumen <NUM> in which a guidewire can slide if it is advantageous.

Turning now to the implantation procedure for the heart prosthesis <NUM>, for each arc <NUM> of the containment portion <NUM> there are inserted the two ends of the guidewire <NUM>, <NUM> which extend through them, in a corresponding pin <NUM> of the two connecting elements <NUM> and then in the catheters <NUM> of the assistance device <NUM>. For example, the guidewire <NUM> runs through, in order, a first catheter <NUM>, a first pin <NUM> of a first connecting element <NUM>, an arc <NUM>, a first pin <NUM> of the other connecting element <NUM> and a second catheter <NUM>, as can be seen in <FIG>.

The catheter <NUM> is then forced to advance inside the main catheter <NUM> and through the mitral valve until the end <NUM> thereof is inside the left ventricle. Although, for greater clarity, <FIG> show only the devices, the operations shown therein are normally carried out inside the heart of the patient.

The central body <NUM> is then pushed so that it advances further inside the catheter <NUM> until the connecting elements <NUM> are released from the catheter. It may be noted that, when the central body <NUM> is in a collapsed configuration, in order to be able to slide inside the catheter, the connecting elements are deformed. However, they are constructed from a shape-memory material so that, once they are out of the catheter, they immediately take up the intended configuration.

In order to join the central body <NUM> and the containment portion <NUM>, or in other words to engage the arcs <NUM> with the connecting elements <NUM>, it is now enough to pull the ends of each guidewire (<FIG>). In this manner, the pins <NUM> of the connecting elements <NUM> are inserted into the axial holes <NUM> of the engagement portions <NUM> which are positioned at the ends of the arcs <NUM>. It may be noted that, for tightening, the presence of the assistance device <NUM> is of primary importance, and in particular of the catheters <NUM>. In fact, the incompressible catheters <NUM> allow the guidewires to be pulled without kinking against the edge of the catheter <NUM>. In other words, the catheters allow a transfer of a traction force, which otherwise could not be applied, to the portion of guidewire inside each arc which is sufficient to connect to each other the arcs <NUM> and the connecting elements <NUM>.

Once the components of the prosthesis are secured to each other, the guidewires can be retrieved as well as the assistance device <NUM> (<FIG>).

Thus, the prosthesis is assembled and maintained in the correct position with the central body <NUM> still inside the catheter <NUM> and the two arcs <NUM> correctly orientated relative to each other so as to constitute the containment portion <NUM> of the prosthesis (<FIG> and <FIG>).

By acting on the release device <NUM> and on the catheter <NUM>, the central body <NUM> of the prosthesis is forced to advance inside the catheter <NUM> while at the same time the catheter <NUM> is withdrawn. The central body is maintained substantially in a stable position inside the heart so that the containment portion <NUM> does not lose contact with the annulus of the native valve while the catheter <NUM> is retrieved. The central body <NUM>, when it is released from the catheter <NUM>, expands inside the native valve until it is constrained by the containment portion <NUM> (<FIG>). The leaflets of the native valve thus remain captured between the central body of the heart prosthesis and the containment portion <NUM>. This configuration brings about a stable and secure positioning of the prosthesis.

All that has been described above must naturally be understood to be one possible embodiment of the invention but not the only one. In an exemplary manner, there will now be described some variants of the objects described above. It should nevertheless be understood that this is not an exhaustive listing of the possible variants.

According to a variant, a second catheter <NUM> and a third catheter <NUM>, visible in cross-section in <FIG>, slide inside the first catheter <NUM> of the guidewire introducer device <NUM>. The second catheter <NUM> provides two lumens <NUM> and <NUM>, suitable for having guidewires sliding therein. The catheter <NUM>, unlike the second catheter <NUM> described above, has a D-shaped cross-section. Preferably, the second catheter <NUM> provides an additional lumen <NUM> for the passage of the wire <NUM> of the deflection system of the distal portion of the catheter.

The third catheter <NUM> also has two lumens 45a, 45b, suitable for accommodating two guidewire capturing devices <NUM>. The third catheter <NUM> also has a D-shaped cross-section which complements the cross-section of the second catheter <NUM>. In this manner, the correct mutual orientation between the catheter <NUM> and the catheter <NUM> is ensured, and therefore between the guidewires which are inserted in the lumens <NUM> and <NUM> and the guidewire capturing devices <NUM>. Easier positioning of the guidewires around the annulus is thereby allowed.

In this regard, it is evident that the D shape is intended to be understood to be exemplary: it is sufficient for the cross-sections of the two catheters <NUM> and <NUM> to be such as to ensure the retention of the correct mutual orientation. For example, the cross-sections of the two catheters <NUM> and <NUM> are mutually complementary inside the catheter <NUM> (in other words, the two cross-sections juxtaposed correspond to the cross-section of the first catheter <NUM> of the guidewire introducer device <NUM>) and the two catheters <NUM> and <NUM> comprise at least one planar abutment face <NUM> and <NUM>, respectively. It will be understood that the catheters <NUM> and <NUM> can slide independently inside the first catheter <NUM>. It is further possible to provide a single lumen 45a.

The third catheter <NUM> further has an additional lumen <NUM> for the passage of a wire of a deflection system of the distal portion of the catheter.

With reference now to <FIG>, a second catheter <NUM> and a third catheter <NUM> may comprise mechanically bendable metal structures. These metal structures constitute the lumens <NUM> and <NUM> of the second catheter <NUM> and the lumens 345a, 345b of the third catheter <NUM>. Each lumen <NUM> and <NUM> has a wire <NUM> which allows it to be bent. Preferably, each lumen <NUM> and <NUM> may form two curves. A first curve is greater than <NUM>°, preferably between <NUM>° and <NUM>°; a second curve is approximately <NUM>°. Preferably, the two curves lay in two mutually perpendicular planes. The two curves are obtained by means of respective portions <NUM> and <NUM> which are suitably perforated in order to create anisotropic sections which advantageously ensure a precise and unambiguous orientation of the lumens. This variant further allows straightening of all the lumens before removal of the second and third catheters. In this manner, the friction is greatly reduced, both in relation to the catheter <NUM>, in which the catheters <NUM> and <NUM> slide, and in relation to the guidewires which slide therein, making it easier and faster to withdraw the second and third catheters. Furthermore, the metal lumens have a thickness which is particularly small.

The catheters <NUM> and <NUM> slide inside the catheter <NUM> in a straightened configuration (<FIG>). When they are externalized from the catheter <NUM>, the deflection is then activated so as to curve the portions <NUM> and to produce the first curves (<FIG>). The distal deflection of the portions <NUM> is then activated in order to produce the second curves (<FIG>). In a generally similar manner, the deflection on the lumens 345a and 345b of the third catheter is also activated. At the end of the operations for positioning the guidewires, all the lumens are straightened (<FIG>) for the extraction thereof.

Claim 1:
A guide wire introduction device (<NUM>) for positioning at least one guide wire around a heart valve comprising:
- a first catheter (<NUM>) which is provided with a distal deflection system,
- a second catheter (<NUM>, <NUM>, <NUM>, <NUM>) which can slide inside the first catheter (<NUM>), comprising at least one lumen (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) which is capable of causing a guide wire to slide therein and which is provided with a distal deflection system (<NUM>, <NUM>, <NUM>) for deflecting the end thereof through an angle greater than <NUM>°, the curvature being directed in the opposite direction to a curvature of an end (<NUM>) of the first catheter (<NUM>).