Device and assembly method for implanting heart valve prostheses

Abstract

To provide a device for implanting a prosthesis for a heart valve.SOLUTION: A device for implanting a heart prosthesis having a central body (16) and a containment portion having one or more sub-components (22) comprises a release device for the central body capable of being inserted into a catheter, and a connection operation assisting device for assisting connection operation between the central body (16) and the sub-components of the containment portion. The connection operation assisting device comprises a catheter assembly including at least two catheters for each sub-component of the containment portion, the catheters being partly joined to each other and each having at least one free end.SELECTED DRAWING: Figure 16

Description

Technical Field

[0001] The present invention relates to an apparatus and an assembly method for implanting a prosthesis for a heart valve.

[0002] The present invention has been developed, without being limited thereto, with particular regard to an apparatus for use in a procedure for implanting a heart prosthesis that replaces the physiological function of a heart valve that is malfunctioning, in particular a procedure for implanting a heart prosthesis for an atrioventricular valve.

Background Art

[0003] The heart valve is a complex and delicate organ that is responsible for the normal function of the human heart. Its main purpose is to make the blood flow in the heart cavity unidirectional, which is essential in both the filling phase of the heart cavity, known as diastole, and the ejection phase of the blood, known as systole.

[0004] To optimize the blood ejection efficiency, the structure of the heart is composed of two different regions, namely the left and right regions, which are further subdivided into two smaller regions, namely the atrium and the ventricle. The right region of the heart, consisting of the right atrium and the right ventricle, receives blood from the peripheral circulation and sends it to the pulmonary circulation for oxygenation. Similarly, the left region, which is subdivided into the left atrium and the left ventricle, supplies the peripheral circulation system, receives oxygenated blood from the pulmonary circulation, and ejects it into the systemic circulation.

[0005] To make the blood flow inside the heart unidirectional, valve membranes are located at the exits of the heart cavities. The valve membranes located at the exits of the atria are called atrioventricular valves because they connect the atrium cavities on each side of the heart to the ventricle cavities. On the right side of the heart, this heart valve is also called the tricuspid valve, and on the left side, it is usually described as the mitral valve. Finally, the heart valve located at the exit from the right ventricle is called the pulmonary valve, and the heart valve located at the exit from the left ventricle is called the aortic valve.

[0006] Diseases that negatively affect the function of the heart valves are among the most serious of all heart diseases. Mitral valve insufficiency, or the inability of the valve to close completely, is a serious valvular dysfunction, stemming from a decrease in the pumping efficiency of the left side of the heart, which is responsible for supplying blood to the entire body.

[0007] In modern medicine, the standard treatment for severe heart valve dysfunction is to replace the heart valve with an implantable prosthesis. If not, repair options exist, primarily for mitral valve dysfunction. In either case, this is achieved through open-heart surgery, which provides direct access to the malfunctioning heart valve. Such procedures require temporarily stopping the heart and creating an artificial extracorporeal blood circulation circuit using appropriate pumps and oxygen exchange equipment. Despite advancements in techniques for managing cardiac arrest and improvements in extracorporeal circulation systems, open-heart surgery carries risks due to its invasiveness and the time required. Indeed, implantable prostheses, commonly used in conventional surgery for both repair and replacement, typically require lengthy procedures to be implanted at the site using specialized suturing techniques. Furthermore, in some cases, surgical intervention may be impossible due to the patient's overall medical condition, such as advanced age or the presence of comorbidities.

[0008] To overcome these limitations, less invasive interventions called transcatheter procedures have been developed. For this purpose, radially foldable prostheses that can be self-implanted at the implantation site are used. These prostheses can be implanted using a catheter that guides through the vascular system and reaches the implantation site through remote access created in peripheral blood vessels such as the femoral artery or other arteries, allowing the cardiac prosthesis to be released. In this way, heart valve dysfunction can be normalized with minimal surgical intervention while the heart is beating. Currently, transcatheter procedures are clinically standardized only for the treatment of aortic valves.

[0009] This situation is different with regard to the treatment of atrioventricular valve dysfunction, particularly mitral valve dysfunction. The complex biomechanisms of the heart valves and their surrounding structures, as well as the diversity of diseases, vary greatly from one another. These directly or indirectly affect the heart valves, making it significantly more difficult to meet the conditions necessary for reliable and effective transplantation to the mitral valve via a transcatheter route.

[0010] In terms of the diversity of individual developed designs, the primary technology developed for transcatheter prostheses of atrioventricular valves provides an apical approach to the heart. This procedure requires a thoracic incision to expose the apex of the left ventricle. The apex is then punctured to allow insertion of an apical port. Through this apical port, the catheters necessary to complete the procedure are successively inserted.

[0011] The problem with this approach is that it can damage very delicate parts of the heart, such as the apex, potentially leading to adverse consequences for the patient, such as bleeding or aneurysms. [Overview of the Initiative]

[0012] The objective of the present invention is to solve the problems of the prior art and, in particular, to provide a procedure for implanting cardiac prostheses transcatheterally without damaging the cardiac apex. Another objective is to provide a safer procedure for patients. Specifically, the objective is to provide a reliable and safe guidewire insertion device and cardiac prosthesis implantation device for use in performing such a procedure. Yet another objective is to provide a procedure for assembling cardiac prostheses using such implantation devices.

[0013] The present invention relates to a guidewire insertion device and a cardiac prosthesis implantation device, both of which have been specifically developed to enable transcatheter implantation via a transseptal access developed by the applicant. The transseptal access is intended to be understood as access to the mitral valve, starting from the peripheral femoral vein, proceeding through the inferior vena cava to the right atrium, and finally reaching the left atrium through an opening created using an interventional technique in the septum between the two atria. The left atrium allows for antegrade access to the mitral valve to be treated. In this way, damage to the left ventricle, i.e., perforation, associated with transapical implantation that provides retrograde access to the mitral valve from the ventricular side is prevented.

[0014] Based on a first embodiment, a guidewire insertion device for positioning at least one guidewire around a heart valve is described. This device can position the guidewire from a transseptal access. This device may comprise a first catheter that can be provided with at least one tip bending system. This device may comprise a second catheter that can be inserted inside the first catheter. The second catheter may have a lumen suitable for sliding the guidewire inward. By providing the second catheter with a tip bending system that preferably bends its end at an angle greater than 90°, it can best reach the area directly below the leaflets of the natural valve. This device may comprise a third catheter. The third catheter can be inserted inside the first catheter. The third catheter may have an internal device for capturing the guidewire. The third catheter may be provided with a tip bending system. The bending system of the second catheter may include a wire.

[0015] Based on another embodiment, a guidewire insertion device is described for positioning at least two guidewires around a heart valve. The second catheter may have two lumens suitable for sliding the guidewires inward. The two lumens can be terminated so that they face substantially opposite directions to each other.

[0016] In an advantageous embodiment, the guidewire insertion device comprises a second catheter. The guidewire insertion device is provided with radiopaque and / or radiopaque components. These radiopaque and / or radiopaque components can be located at the tip of the second catheter, preferably embedded within it.

[0017] In another embodiment, the guidewire insertion device may include a single-lumen first catheter.

[0018] A procedure for positioning at least one guidewire around a heart valve is described based on another embodiment. This procedure may include a step of providing access to a first catheter from a vein, preferably from the femoral vein. The first catheter may be introduced into the right atrium from the inferior vena cava (IVC). An opening may be made in the septum between the two atria to access the left atrium. This procedure may include a step of inserting a guidewire insertion device into the left ventricle, passing through the mitral valve, and positioning one or more guidewires around the spontaneous valve.

[0019] A procedure for positioning at least one guidewire around a heart valve, based on a preferred embodiment, is described below, but this procedure includes, • A step of providing access for the first catheter from a vein, The first catheter is inserted into the right atrium from the inferior vena cava and then into the left atrium through the septal opening between the two atria. The steps include inserting a guidewire insertion device into the left ventricle, passing it through the mitral valve, and positioning one or more guidewires around the natural valve, It includes.

[0020] A cardiac prosthesis implantation device will be described based on another embodiment. The cardiac prosthesis may comprise a central body and a restraint section. The restraint section may be subdivided into one or more segmented elements. The cardiac prosthesis implantation device may include a release device for the central body. The release device may be inserted into the catheter. The cardiac prosthesis implantation device may have a device to assist in the connection operation between the central body and the segmented elements of the restraint section. The device to assist in the connection operation between the central body and the segmented elements of the restraint section may comprise a catheter assembly. There may be at least two catheters in each segmented element of the restraint section. These catheters may be connected in part to each other and each may have at least one free end. These catheters may be grouped together in the same sheath. The sheath may group these catheters along part of itself. The sheath may leave at least one end free for each catheter. The sheath may further comprise an additional lumen for a guidewire, preferably for the central catheter.

[0021] Advantageously, the catheters that make up the catheter assembly can be securely connected to each other.

[0022] In another embodiment, the device assisting the connection operation between the central body and the dividing element of the binding portion may include a longitudinally incompressible catheter assembly. In this way, an incompressible adjacent passage for the guide wire is formed during use. Preferably, the catheter constituting the catheter assembly may be flexible.

[0023] A procedure for assembling a cardiac prosthesis will be described based on another embodiment. The cardiac prosthesis may have a central body and a restraint section. The restraint section may be subdivided into one or more segmented elements. The procedure may include inserting a guidewire into each segmented element of the restraint section. This may include sliding each segmented element so that both ends of the guidewire are outside the segmented element itself. The procedure may include inserting each end of the guidewire into the corresponding connecting member for each segmented element of the restraint section in order to connect the central body and the restraint section. The procedure may include inserting each end of the guidewire into the corresponding catheter of the catheter assembly. This may include pulling the end of each guidewire to connect the segmented elements of the restraint section to the central body and the restraint section.

[0024] A procedure for implanting a cardiac prosthesis is also described based on another embodiment. The cardiac prosthesis may comprise a central body and a restraint portion subdivided into one or more segmented elements. The procedure may include a step of providing access for a first catheter from a vein. Preferably, access can be provided to the femoral vein. The procedure may include a step of inserting the first catheter from the inferior vena cava (IVC). The first catheter may be inserted into the right atrium. An opening can be made in the septum between the two atria. Access to the left atrium can be provided through this opening. The procedure may include a step of providing one or more guidewires around the natural valve. This operation can be performed using a guidewire insertion device. It is possible to insert the segmented elements of the restraint portion. The procedure may include a step of inserting a cardiac prosthesis implantation device. The central body can then be connected to the segmented elements 22 of the restraint portion 18. Release of the central body in a predetermined position can be achieved by pushing the central body out of the device for implantation.

[0025] According to another aspect, the procedure for implanting the cardiac prosthesis involves sliding each segmented element using at least one guide wire disposed around the native valve, and preferably sliding each segmented element covering (covering the wire) at least one guide wire, thereby providing a step of inserting each segmented element into the heart.

[0026] According to another aspect, the procedure for implanting the cardiac prosthesis can involve using a cardiac prosthesis implantation device comprising an auxiliary device that can have a catheter assembly and that assists in the connection operation of connecting the segmented element of the constriction part and the central body. This procedure can include steps of inserting each end of a guide wire into a corresponding connecting member for connecting the central body and the constriction part, and inserting each end of the guide wire into a corresponding catheter of the catheter assembly at its free end. This procedure can further include a step of establishing a connection between the central body and the segmented element of the constriction part by acting on each end of the guide wire.

[0027] Based on another aspect, a procedure for implanting a cardiac prosthesis comprising a central body of a prosthetic valve tip and a constriction part subdivided into one or more segmented elements will be described. This procedure includes: · providing access to a first catheter from a vein; · inserting the first catheter from the inferior vena cava into the right atrium and accessing the left atrium through a septal hole; · providing one or more guide wires around the native valve; · inserting the segmented element of the constriction part; · inserting a cardiac prosthesis implantation device; · connecting the central body to the segmented element of the constriction part; · pushing the central body until the central body is released at a predetermined position; and is included.

[0028] The procedure for implanting the cardiac prosthesis is further described, in which each segment is inserted by sliding it onto one of the guide wires positioned around the natural valve.

[0029] Advantageously, a cardiac prosthesis implantation device having all or some of the above features is used as a procedure for implanting a cardiac prosthesis, and according to this procedure, after inserting each segment, for each segment of the binding portion, - The step of inserting each end of the guide wire into the corresponding connecting member in order to connect the central body and the binding portion, The steps include inserting each end of the guidewire into the corresponding catheter of the catheter assembly at its free end, The steps include: pulling each end of the guide wire to create a connection between the central body and the dividing element of the binding portion; This is performed. Preferably, access is provided by the femoral vein. [Brief explanation of the drawing]

[0030] Solutions according to one or more embodiments of the present invention, as well as additional features and relative advantages, will be better understood by referring to the following detailed description, which is given purely as non-limiting embodiments and is intended to be interpreted together with the accompanying drawings. For simplicity, corresponding components are denoted by the same or similar reference numerals and their descriptions will not be repeated. In this regard, it will be clearly understood that the figures are not necessarily to scale, some details may be exaggerated and / or simplified, and unless otherwise specified, they are used only to conceptually illustrate the structures and procedures described. In particular,

[0031] [Figure 1] Figure 1 is a schematic diagram of a cardiac prosthesis for treating heart valves according to an embodiment of the present invention. [Figure 2] Figure 2 shows the cardiac prosthesis from Figure 1 in a disassembled state. [Figure 3] Figure 3 illustrates the steps of the procedure for implanting a cardiac prosthesis, which is accessed through the interatrial septum. [Figure 4] Figure 4 shows details of the second catheter of the guidewire insertion device. [Figure 5] Figure 5 is a separate drawing showing the same details as Figure 4. [Figure 5a] Figure 5a shows a modified example of the second catheter of the guidewire insertion device. [Figure 6] Figure 6 illustrates the steps of the cardiac prosthesis implantation procedure, showing the second catheter of the guidewire insertion device advancing towards the mitral valve. [Figure 7] Figure 7 illustrates the steps of the cardiac prosthesis implantation procedure, showing how the second catheter of the guidewire insertion device advances through the mitral valve into the left ventricle. [Figure 8] Figure 8 shows the steps in Figure 7 viewed from a closer perspective. [Figure 9] Figure 9 illustrates the steps of the cardiac prosthesis implantation procedure, with the guidewire capture device positioned. [Figure 10] Figure 10 shows the steps of the procedure for implanting a cardiac prosthesis, with the first guidewire positioned. [Figure 11] Figure 11 shows the steps of the procedure for implanting a cardiac prosthesis after the positioning of the first guidewire is complete. [Figure 12] Figure 12 illustrates the steps of the cardiac prosthesis implantation procedure, with the division elements of the restraint portion of the cardiac prosthesis inserted. [Figure 13] Figure 13 shows the steps of the cardiac prosthesis implantation procedure, with the cardiac prosthesis implantation device inserted. [Figure 14] Figure 14 is a diagram showing an auxiliary device that assists in the connection operation between the central body and the dividing element of the binding section. [Figure 15] Figure 15 is a cross-sectional view of the apparatus shown in Figure 14. [Figure 16] Figure 16 shows the steps of the procedure for implanting a cardiac prosthesis, with the central body progressing. [Figure 17] Figure 17 illustrates the steps in the procedure for implanting a cardiac prosthesis, showing how the central body and the binding portion's dividing elements are connected. [Figure 18]Figure 18 illustrates the steps in the procedure for implanting a cardiac prosthesis, after which the auxiliary device is removed. [Figure 19] Figure 19 shows a cardiac prosthesis in a shape ready for in-situ opening. [Figure 20] Figure 20 shows a cardiac prosthesis, illustrated inside the heart and ready for in-situ access. [Figure 21] Figure 21 shows a cardiac prosthesis in a properly positioned state. [Figure 22] Figure 22 is a cross-sectional view showing modified examples of the second and third catheters of a guidewire insertion device. [Figure 23] Figure 23 shows another variation of the second and third catheters of the guidewire insertion device. [Figure 24] Figure 24 shows another variation of the second and third catheters of the guidewire insertion device. [Figure 25] Figure 25 shows another variation of the second and third catheters of the guidewire insertion device. [Figure 26] Figure 26 shows another variation of the second and third catheters of the guidewire insertion device. [Modes for carrying out the invention]

[0032] Referring to the drawings, Figures 1 and 2 illustrate an implantable cardiac prosthesis 10 used to replace the function of an atrioventricular valve.

[0033] The cardiac prosthesis 10 is equipped with a prosthetic structure 12 that supports and connects to the natural valve, and a group of flexible artificial valve leaflets 14 are fixed inside. In particular, the prosthetic structure 12 has • Central body 16 and, • The binding part 18 and, • A connecting member 20 for connecting the central body 16 and the binding portion 18, It is equipped with.

[0034] The prosthetic structure 12 is configured such that each of its components can be folded without affecting the function and safety of the cardiac prosthesis. Therefore, by temporarily reducing the radial dimensions of the prosthesis, it can be introduced into the heart chamber through a small-diameter access port, which is suitable for minimally invasive surgical techniques, and in particular for transcatheter positioning and implantation of cardiac prostheses according to the present invention. In other words, it is possible to insert a cardiac prosthesis 10, which can be delivered into the heart chamber near the implantation site through a minimally invasive access, and then placed and implanted there to functionally replace a natural valve, into a catheter of a small diameter.

[0035] The following describes in detail how the prosthetic structure 12 is disassembled into various parts.

[0036] The central body 16 is part of a prosthetic structure 12 that defines the boundary of the conduit through which blood flows. A flexible artificial valve leaflet 14 is fixed inside the central body 16, and the flexible artificial valve leaflet 14 makes the blood flow unidirectional inside the conduit, which is known, for example, from Italian Patent No. 0001422040 by the present applicant.

[0037] The central support portion 16 is an elastic structure that can be folded radially, and due to its elastic recovery properties, it has the property of expanding to a diameter exceeding the maximum diameter at which contact is maintained, that is, to a diameter exceeding the maximum diameter at which connection with the free edge of the closed artificial valve leaflet 14 is maintained.

[0038] The restraining portion 18 is part of the artificial organ structure that restricts the free expansion of the central support portion 16, preventing it from exceeding the maximum radius suitable for maintaining the joint between the artificial valve leaflets 14. The restraining portion 18 has a substantially annular shape and is non-stretchable in the longitudinal direction, meaning that even if the central support portion 16 expands internally and radial forces are applied externally, its circumferential length does not change significantly.

[0039] The binding portion 18 is preferably subdivided into two substantially arc-shaped and separated dividing elements 22, which for simplicity will be referred to below as "arc portions". Each arc portion 22 is selectively engageable with the connecting member 20, thereby ensuring a secure connection in the final transplant shape.

[0040] Each end 24 of the segment element 22 is provided with an engaging portion 26, which may preferably be oriented outward from the valve ring surface. In the illustrated embodiment, the engaging portion 26 is oriented substantially perpendicular to the surface of the valve ring. That is, each connecting member 20 is provided with a pin 28, which is suitable for being received into an axial hole 27 located within each engaging portion 26. Each of these two connecting members 20 has a pair of pins 28, which are positioned substantially at an angular position directly opposite the central body 16. In addition to these pins 28, the engaging portions 26 at the ends of each arc portion 22 of the binding portion 18 may be provided with a barb, lip or other surface discontinuity intended to create mechanical interference between these portions and / or increase the friction of the pin / cavity connection, thereby improving the stability of the connection between each segment element 22 of the binding portion 18 and the connecting member 20. The pin 28 is oriented to align with the orientation of the engaging portion 26 present on the dividing element 22 of the binding portion 18, and the pin-cavity connection ensures that the binding portion is kept in a plane that is geometrically consistent with the natural valve ring. Furthermore, the axial penetration of the pin 28 ensures a passage for the guide wire, as will be described in more detail below.

[0041] It is clear that the pin / cavity coupling mechanism could instead have a pin at the end of the dividing element 22 and a cylindrical cavity within the connecting member 20. More generally, this pin / cavity coupling is for illustrative purposes only and is not intended to limit the concept of the solution in any way.

[0042] Naturally, this prosthesis can also have various numbers of segmented elements 22. For example, having one segmented element allows it to be formed like an open ring. The configuration described with two segmented elements 22 is preferred, as this allows the use of two guidewires, making precise positioning easier with the guidewire introduction device described below compared to a single guidewire that may become entangled in the chordae tendineae. However, a third segmented element does not facilitate the positioning operation and is therefore essentially unnecessary, but it should not be excluded.

[0043] During use, the leaflets of the natural valve remain trapped within the joint between the central body 16 and the restraining portion 18. Furthermore, the restraining portion 18 stabilizes the natural valve annulus and prevents the radial force exerted by the central support portion 16, which is necessary to ensure the effective placement of the prosthesis, from being transmitted to the surrounding biological structure. This surrounding biological structure is typically affected by degenerative and dilatation processes associated with diseases that cause atrioventricular valve dysfunction.

[0044] For clarity, in Figures 1 and 2, and in subsequent drawings, the outer diameter of the central support 16 is shown to be smaller than the inner diameter of the restraint 18. In other words, these drawings illustrate these two parts of the prosthesis 12 not in contact with each other in their fully expanded form. In reality, the central support 16 can be larger than the restraint 18. In this case, there is interference between the two parts of the prosthesis 12, and as the restraint 18 exerts an inhibitory effect on expansion, the central support 16 effectively exerts a radial force on the restraint 18, regardless of the thickness of the tissue trapped between the two parts of the prosthesis 12. This radial pressure improves the stability of the natural valve's placement on the valve leaflet.

[0045] Next, a preferred procedure for implanting the cardiac prosthesis 10 described above will be explained.

[0046] First, access is provided via the femoral vein or iliac vein. Access via the femoral vein is preferred if possible, as it is significantly easier and more direct. In particular, it does not require invasive surgical procedures. An insertion catheter can be used primarily for the purpose of protecting the femoral vein, which has a smaller diameter.

[0047] The introduction catheter, if present, is located in the femoral vein, thereby creating access to a larger diameter vessel. Subsequently, the main catheter 32 is inserted and slides inside the introduction catheter, and once provided, slides through the inferior vena cava (IVC) to the right atrium, as can be seen in Figure 3.

[0048] The main catheter 32 is equipped with a tip bending system, and its end 34 is configured to be bent towards the left atrium by the operator. Subsequently, a puncture is performed on the septum S between the two atria, allowing access to the left atrium. A guidewire insertion device 36 is inserted inside the main catheter 32.

[0049] As described above, it is not always necessary to provide an induction catheter; instead, the main catheter 32 can be used directly to provide access to the right atrium from the inferior vena cava. Furthermore, the main catheter can be inserted into the left atrium, allowing the guidewire insertion device 36 to be inserted directly into the left atrium.

[0050] The guidewire insertion device 36 is a device that has the function of positioning the guidewire, which is necessary for later positioning of the cardiac prosthesis 10, around the leaflets of the biological mitral valve V.

[0051] The guidewire insertion device 36 is equipped with a first catheter 40, and the second catheter 44 and the third catheter 45 slide inside the first catheter 40. The first catheter 40 is a single-lumen catheter. A tip bending system is provided, and its tip 42 is configured to be directed towards the mitral valve V by the operator.

[0052] The second catheter 44, as detailed in Figures 4 and 5, is provided with two lumens 46 and 48, both suitable for sliding a guidewire inside. These two lumens are positioned parallel and adjacent to each other for most of the second catheter 44. At the end 50 of the second catheter 44, these two lumens are curved at an angle of approximately 90 degrees in substantially opposite directions. The two lumens 46 and 48 therefore terminate not at the tip 51 of the catheter 44, but at their respective holes 41 and 43 on either side at its opposing position. In other words, the two guidewires inserted into the lumens 46 and 48 exit the second catheter 44 pointing in opposite directions to each other.

[0053] The second catheter 44 further includes a bending system. In the illustrated embodiment, the bending system includes a wire 52. The wire 52, fixed to the end 50 of the catheter, extends a short distance outside the catheter before re-entering the catheter. The operator simply pulls the wire 52 to form a curve in the second catheter 44, which can be emphasized as clearly seen in Figure 4. This curve exceeds 90 degrees. However, it is not impossible to use other bending systems. For example, a portion made of shape-memory material can be incorporated inside the second catheter 44 and inserted in an extended state inside the first catheter 40, so that the precise curve is reproduced when it is pushed out of the first catheter 40. An example of such a configuration is shown in Figure 5a, in which a wire 152 made of a shape-memory material such as titanium-nickel alloy (nitinol) is incorporated inside the second catheter 144.

[0054] The tip 51 is provided with a portion 53 made of a radiopaque or echopaque material. This portion 53 is preferably embedded inside the rounded tip 51 to prevent accidental damage.

[0055] The third catheter 45 is inserted inside the first catheter 40, as will be described in more detail below, and receives a guidewire capture device 47 (snare device), as will be described in more detail below. It should be noted that the illustrated guidewire capture device, which is provided with a collection of various foldable rings or loops, is one of many possible capture devices that can be used and is considered particularly effective for specific applications. However, various capture devices having, for example, a single loop or a different number of loops than the illustrated device are not excluded.

[0056] Returning to the procedure for implanting the cardiac prosthesis, the guidewire insertion device 36, inserted inside the main catheter 32, travels through the septum S into the left atrium (Figure 3). It can be noted that the end 34 of the main catheter 32 can be located in the right atrium or in the left atrium, as shown in the illustration. The end 42 of the first catheter 40 of the guidewire insertion device 36 is bent toward the heart valve V, that is, toward the bottom in Figure 6.

[0057] The second catheter 44 of the guidewire insertion device 36 is formed to slide inside the first catheter 40 of the guidewire insertion device 36 (Figure 6). The end 50 protrudes and has a distinct curve oriented in the opposite direction to the curve of the end 42 of the first catheter 40. In fact, the second catheter 44 is curved upward in Figure 6.

[0058] The guidewire insertion device 36 advances further inside the main catheter 32 (Figure 7), and the second catheter 44 enters the left ventricle through valve V.

[0059] As the second catheter 44 of the guidewire insertion device 36 enters the left ventricle, its tip 51 retracts slightly so that it is positioned behind the posterior leaflet of the natural valve. In particular, the tip 51 is preferably positioned behind the central portion (valve villi), usually indicated as P2. For this reason, the presence of a portion 53 made of radiopaque material at the tip 51 is particularly advantageous. If there is any doubt regarding the precise positioning or orientation of the catheter end 50, it can be directly confirmed using an ultrasound probe or fluoroscopy. The portion 53 made of radiopaque material is oriented tangentially to the edge of the heart valve.

[0060] Figure 8 is a detailed schematic diagram of the left ventricle, in which the biological mitral valve V is clearly visible along with the aortic valve A, in addition to the two bundles of chordae tendineae T. The end 50 of the second catheter 44 of the guidewire insertion device 36 is correctly positioned behind the posterior leaflet of the natural valve V. Note that the catheter 44 does not cross the bundles of chordae tendineae.

[0061] Referring now to Figure 9, the third catheter 45, which has a guidewire capture device 47 inside, slides along the inside of the first catheter 40 until it is introduced into the left ventricle. The second catheter also has a bending system 56 at its end 54. This bending system can generally be the same as the wire 52 described above for the second catheter 44. However, according to a preferred modification, a wire can be provided that slides along the inside of the catheter wall for structural simplicity. The bending effect is produced by a flexible metal structure in which a rigid skeleton is embedded in the width portion of the catheter. However, other known mechanisms in the conventional are not to be excluded. Furthermore, the guidewire capture device 47 is inserted into the cover sheath 55.

[0062] The third catheter 45 is oriented such that its end 54 curves in the opposite direction to the curve of the end 50 of the second catheter, that is, its end 54 curves toward the aortic valve. The guidewire capture device 47 is pushed out from the corresponding third catheter 45 and sheath 55 until it is positioned in the LVOT (left ventricular outflow tract), that is, prior to the aortic valve.

[0063] By maintaining the guidewire capture device 47 in this position, the first guidewire 56 is inserted into the first lumen 46 of the second catheter of the guidewire insertion device 36. The end 57 of the guidewire 56 is pushed into the ventricle by the operator (Figure 10). The end 57 of the guidewire 56 is moved around the valve toward the LVOT by the effect of precisely positioning the tip 51 of the second catheter 44, precisely positioning the lateral position of the exit 41 of the lumen 46, and precisely positioning the heart, as well as by the effect of blood flow that naturally directs toward the aortic valve A during systole. Upon reaching the LVOT, it is captured by the guidewire capture device 47, which had been positioned beforehand. Subsequently, the end 57 of the guidewire 56 is retrieved by pulling the third catheter 45.

[0064] In some cases, the guidewire capture device 47 can be positioned inside the aorta, that is, on the other side of the aortic valve A. The guidewire is then pushed into the aorta by the blood flow, thereby enabling the capture operation.

[0065] When the end 57 of the guide wire 56 is caught, the guide wire 56 forms a half-loop around the valve V (Figure 11).

[0066] Generally, a similar half-loop is formed around the valve V using a second guidewire 58 inserted into the second lumen 48 of the second catheter 44 in a symmetrical manner. In this way, the valve V is completely surrounded by two guidewires 56, 58, both correctly positioned. For this purpose, the same guidewire capture device 47 used to capture the first wire can be used, or preferably another guidewire capture device 47 received in the third catheter 45. In this case, the third catheter 45 preferably has a double lumen.

[0067] Naturally, it is also possible to position a single guidewire that makes a complete loop around the natural valve using a guidewire positioning device similar to those detailed above. However, in this case, the guidewire positioning procedure becomes more complex. Although fewer steps are required (the second wire step does not need to be repeated), it is not easy to orient the guidewire around the entire circumference of the valve in a sufficiently precise manner due to the risk of it becoming entangled in the chordae tendineae. Using two guidewires allows us to utilize the shape of the heart and the body's blood flow to facilitate the operation and minimize the risk of errors that could have serious consequences for the patient if not immediately detected and treated.

[0068] Next, referring to Figure 12, the first catheter 40 and the second catheter 44 are preferably positioned in this step to facilitate the insertion of the two arcs 22 that constitute the binding portion 18 of the cardiac prosthesis 10 into the ventricle. The two arcs are inserted covering the wire, that is, they are inserted sliding along the surface of the guidewire. In other words, the end 57 of the recently retrieved guidewire 56 is inserted into the interior by using the longitudinal passage extending through one of the two arcs. Similarly, the end of the guidewire 58 is inserted into the longitudinal passage extending through the other arc. Both of these arcs 22 are pushed out of the first catheter 40 and into the heart. The arcs 22 are pushed until they contact the tip 51 of the second catheter 44. At this point, the first catheter 40 and the second catheter 44 can be removed.

[0069] It is preferable to place the main catheter 32 in the appropriate location and then use it to introduce the device 60 into which the cardiac prosthesis with the central body 16 inserted will be implanted. Removal of the main catheter 32 or replacement with another catheter is not excluded.

[0070] The cardiac prosthesis implantation device 60, whose details are shown in Figures 13, 14, and 15, is equipped with a catheter 61 through which all other components and the central body 16 of the cardiac prosthesis are inserted.

[0071] The cardiac prosthesis implantation device further includes a release device 62 for the central body 16 of the cardiac prosthesis. The release device 62 is suitable for insertion into a catheter to advance the central body 16 of the cardiac prosthesis internally. The cardiac prosthesis implantation device 60 further includes an auxiliary device 64 to assist in the connection operation between the central body 16 and the dividing elements of the binding portion 18. This auxiliary device 64 comprises a catheter assembly 66, of which at least two for each arc of the binding portion are grouped together in the same sheath 68, the sheath 68 partially covering the catheter and leaving at least one free end 70 for each catheter.

[0072] In the illustrated preferred case, where the cardiac prosthesis is provided with two arc portions 22, the auxiliary device 64 is provided with four catheters 66. Naturally, if the cardiac prosthesis is provided with one segment of the restraint portion 18, two catheters would be sufficient. However, if the cardiac prosthesis is provided with three or more segment portions, six or more catheters will be provided.

[0073] Each catheter 66 is incompressible in the longitudinal direction and flexible. Furthermore, they are fixed inside the sheath 68 so as not to slide against each other. Preferably, the sheath 68 further comprises a free longitudinal lumen 72 from which a guidewire can slide if beneficial.

[0074] Next, considering the implantation of the cardiac prosthesis 10, the two ends of the guidewires 56 and 58 are inserted through each arc portion 22 of the binding portion 18, and extend from the corresponding pins 28 of the two connecting members 20 into the catheter 66 of the auxiliary device 64. For example, as can be seen in Figure 13, the guidewire 56 passes through the first catheter 66, the first pin 28 of the first connecting member 20, the arc portion 22, the first pin 28 of the other connecting member 20, and the second catheter 66 in this order.

[0075] The catheter 61 then advances inside the main catheter 32, through the mitral valve, until its end 63 enters the inside of the left ventricle. For clarity, only the apparatus is shown in Figures 16-19, but the illustrated procedure is typically performed inside a patient's heart.

[0076] Subsequently, the central body 16 is pushed and advances further inside the catheter 61 until the connecting member 20 is released from the catheter. Note that when the central body 16 is in a folded shape, the connecting member is deformed to allow it to slide inside the catheter. However, since these are made of shape-memory material, once they are outside the catheter, they immediately return to their desired shape.

[0077] To connect the central body 16 and the binding portion 18, or in other words, to engage the arc portion 22 with the connecting member 20, it is sufficient to pull the end of each guide wire (Figure 17). In this way, the pin 28 of the connecting member 20 is inserted into the axial hole 27 of the engaging portion 26 located at the end of the arc portion 22. The presence of an auxiliary device 64, particularly the catheter 66, is mainly important for tightening. In fact, the incompressible catheter 66 allows the guide wire to be pulled without kinking against the edge of the catheter 61. In other words, the catheter can transmit sufficient tensile force (which cannot be provided without it) to the portion of the guide wire inside each arc portion to connect the arc portion 22 and the connecting member 20 to each other.

[0078] Once the components of the cardiac prosthesis are fixed to each other, the auxiliary device 64 can be retrieved in addition to the guide wire (Figure 18).

[0079] Therefore, the cardiac prosthesis can be assembled and maintained in the correct position with the central body 16 remaining inside the catheter 61, and the two arc portions 22 correctly oriented toward each other so that the binding portion 18 of the cardiac prosthesis is formed.

[0080] By acting on the release device 62 and the catheter 61, the central body 16 of the cardiac prosthesis is advanced inside the catheter 61, and the catheter 61 is withdrawn at the same time. The central body is substantially held in a stable position inside the heart, so as to ensure that the catheter is retrieved so that the restraint portion 18 does not lose contact with the annulus of the natural valve. Once released from the catheter 61, the central body 16 expands inside the natural valve until it is restrained by the restraint portion 18 (Figure 21). The leaflets of the natural valve are therefore trapped between the central body of the cardiac prosthesis and the restraint portion 18. This shape ensures stable and secure positioning of the prosthesis.

[0081] It should be understood that everything described above is, of course, one possible embodiment of the present invention, but not the only embodiment. In an illustrative manner, several variations relating to the above objectives are described here. However, it should be understood that this does not exhaustively cover all possible variations.

[0082] According to a modified embodiment of the present invention, the second catheter 244 and the third catheter 245, as shown in the cross-sectional view of Figure 22, slide inside the first catheter 40 of the guidewire insertion device 36. The second catheter 244 is provided with two lumens 46, 48 suitable for sliding the guidewire inside. Unlike the second catheter 44 described above, the catheter 244 has a D-shaped cross-section. Preferably, the second catheter 244 is provided with an additional lumen 250 for the passage of the wire 52 of the curved system at the tip of the catheter.

[0083] The third catheter 254 also has two lumens 45a, 45b suitable for receiving two guidewire capture devices 47. The third catheter 245 also has a D-shaped cross section that complements the cross section of the second catheter 244. In this way, proper mutual orientation is ensured between catheters 244 and 245, and therefore proper mutual orientation is ensured between the lumens 46, 48 and the guidewires inserted into the guidewire capture devices 47. Thus, the guidewires can be positioned more easily around the valve annulus.

[0084] In this regard, it is clear that the D shape is intended to be understood as illustrative, and it is sufficient that the cross-sectional shapes of the two catheters 244, 245 ensure the maintenance of normal relative positioning. For example, the cross-sectional areas of the two catheters 244, 245 are complementary within the catheter 40 (in other words, these two juxtaposed cross-sections correspond to the cross-section of the first catheter 40 of the guidewire insertion device 36), and these two catheters 244, 245 each have at least one planar contact surface 270, 272. These catheters 244, 245 can be understood to be able to slide independently within the first catheter 40. It is also possible to provide a single lumen 45a.

[0085] The third catheter 245 is further provided with an additional lumen 260 for the wire passage of the curved system at the tip of the catheter.

[0086] Referring next to Figures 23-26, the second catheter 344 and the third catheter 345 can be provided with mechanically bendable metal structures. These metal structures comprise the lumens 346, 348 of the second catheter 344 and the lumens 345a, 345b of the third catheter 345. Each lumen 346, 348 is provided with a wire 352 for bending. Preferably, each lumen 346, 348 may have two bends. The first bend is greater than 90°, preferably between 120° and 180°, and the second bend is approximately 90°. Preferably, the two bends are located in two mutually perpendicular planes. These two bends are obtained using respective portions 354, 356 which are suitably perforated to create anisotropic portions that advantageously ensure the precise and reliable orientation of the lumens. This modified embodiment allows all lumens to be straightened before removal of the second and third catheters. In this way, both the friction between catheters 344 and 345 and catheter 40, and the friction between catheters 344 and 345 and the guide wire sliding inside are greatly reduced, making it easier and faster to withdraw the second and third catheters. Furthermore, the metal lumen has a particularly small thickness.

[0087] Catheters 344 and 345 slide inside catheter 40 in a straight shape (Figure 24). When they exit catheter 40, deflection occurs, causing section 354 to bend and creating a first curve (Figure 25). Subsequently, deflection at the tip of section 356 creates a second curve (Figure 26). Generally in a similar manner, deflection occurs in lumens 345a and 345b of the third catheter. At the end of the guidewire positioning operation, all lumens are straightened for withdrawal (Figure 24).

[0088] Naturally, the principle of the present invention remains the same, and the details of the form and configuration of the embodiments can be significantly altered with respect to those described and illustrated without departing from the scope of the present invention.

Claims

1. A device (64) for assisting the connection operation between a central body (16) and one or more segmented elements (22) of a binding portion (18) provided in a cardiac prosthesis, wherein the device comprises a catheter (66) assembly, and the catheters forming the catheter assembly are not compressible in the longitudinal direction, are partially connected to each other and fixed so as not to slide relative to each other, and each has at least one free end (70).

2. The apparatus according to claim 1, characterized in that the catheter (66) constituting the catheter assembly is flexible.

3. The apparatus according to claim 1 or 2, characterized in that the catheters (66) constituting the catheter assembly are grouped together in the same sheath (68), and the sheath holds the catheters together along a part of it.

4. The apparatus according to claim 3, characterized in that the sheath is further provided with a longitudinal lumen (72).

5. The apparatus according to any one of claims 1 to 4, characterized in that the catheter assembly has at least four catheters (66).

6. The apparatus according to any one of claims 1 to 5, characterized in that the catheter assembly comprises at least two catheters (66) for each dividing element (22) of the binding portion (18).

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