WO2011044994A1

WO2011044994A1 - A device for correcting mitral regurgitation which can be combined with a prosthesis for annuloplasty, and kit comprising such a device

Info

Publication number: WO2011044994A1
Application number: PCT/EP2010/006046
Authority: WO
Inventors: Philippe Primo Caimmi; Giovanni Vacca
Original assignee: Universita' Degli Studi Del Piemonte Orientale "Amedeo Avogadro"
Priority date: 2009-10-16
Filing date: 2010-10-04
Publication date: 2011-04-21
Also published as: ITTO20090785A1; IT1396078B1

Abstract

A device for correcting the mitral regurgitation comprises a corrective structure (22, 26, 28; 42; 52, 56) adapted to engage at least one of the leaflets (AL, PL) of the mitrale valve. Such a corrective structure is provided with a fixing system (25; 55) for fixing the corrective structure to a base. Such a base consists of a prosthesis (10) for mitral anuloplasty that comprises an annular structure (11) composed by a flexible support segment (12), adapted to be fixed by suture along a posterior portion (PMA) of the mitral annulus (MA) extending from the anterolateral trigone (AT) to the posteromedial trigone (PT), and by an intertrigonal rigid segment (13) interconnecting the ends (12a, 12b) of the flexible support segment. The rigid intertrigonal segment is adapted to act as a spacer between the anterolateral trigone and the posteromedial trigone. The annular structure is adapted to be fixed to the mitral annulus exclusively through the flexible support segment. The base for the corrective structure is constituted by the intertrigonal rigid segment of the prothesis.

Description

A device for correcting mitral regurgitation which can be combined with a prosthesis for annuloplasty, and kit comprising such a device

The present invention refers to a device for correcting mitral regurgitation, comprising a corrective structure adapted to engage at least one of the leaflets of the mitral valve .

As it is known, mitral insufficiency relapse is a natural occurence that follows mitral surgical repair both at short and long term, that may reach up to 6% at the discharge, and more than 15% up to 10 years. Presently, the one and only treatment for relapse is a new surgical operation.

However, high invasivity and resulting high surgical risk make a new surgical operation a problematic decision in patients affected by relapse, so that such a decision is deferred with serious consequences for the outcome of the patient .

An object of the present invention is to propose a device for correcting the mitral regurgitation which can be implanted in the simplest and less invasive manner, and which is therefore adapted, in particular, to correct mitral insufficiency relapse .

According to the invention, such an object is reached by a device of the type defined at the beginning, wherein said corrective structure is provided with fixing means for fixing said corrective structure to a base, in which said base is provided with a prosthesis for mitral annuloplasty comprising an annular structure composed of a flexible support segment, which is adapted to be sutured along a posterior portion of the mitral annulus extending from the anterolateral trigone to the posteromedial trigone, and of a rigid intertrigonal segment interconnecting the ends of the flexible support segment, said rigid intertrigonal segment being adapted to act as a spacer between said anterolateral trigone and posteromedial trigone, in which said annular structure is adapted to be fixed to the mitral annulus exclusively through the flexible support segment, and in which said base for the corrective structure consists of the rigid intertrigonal segment of the prosthesis.

By virtue of the fact that the rigid segment of the annular structure of the prosthesis is used as a base for installing the corrective device, implantation of such a device turns out to be relatively simple, with the following advantages:

non-invasivity of the procedure, since implantation can be carried out in an hemodynamics laboratory, the patient being sedated;

repeatability of the corrective procedure;

staying in hospital times extremely reduced: 1-2 days (as for a coronary angiography) ;

low risk of mortality.

Particular embodiments of the invention are the subject of the dependent claims, the content of which has to be considered as an integrating part of the present description.

Further characteristics and advantages of the invention will appear from the following detailed description, provided solely as non-limitative example, and referred to the appended drawings, in which:

figure 1 shows a view of the mitrale valve from the the left ventricle;

figure 2 is a simplified elevational view of a prosthesis according to the invention;

figure 3 is a view analogous to figure 1, in which it is also shown the prosthesis of figure 2 in the implanted condition;

figure 4 shows a sagittal section of the left ventricle with the prosthesis of figure 2 implanted in its annular position;

figure 5 is a view analogous to figure 3, in which the prosthesis is coupled to a clip device for valve repairing according to the Alfieri's technique;

figures 6 to 11 show a method for implantation of the clip shown in figure 5;

figure 12 is a view analogous to figure 3, in which the prosthesis is coupled to an occluding device;

figure 13 shows a method for implantation of the occluding device shown in figure 7; and

figures 14 to 16 show a further embodiment for making a correction device, as well as a method for implantation of such a device.

Figure 1 shows a view of the mitrale valve MV from the left ventricle. The front leaflet and the posterior leaflet of the mitral valve are indicated AL and PL, respectively, and the mitral annulus is indicated MA. The heart strings are indicated CT, while the zones marked by the hatched circles APM and PPM represent the positions of the anterolateral papillary muscle and of the posteromedial papillary muscle, respectively. AT and PT indicate the anterolateral trigone and the posteromedial trigone, respectively, while IT indicates the intervalvular trigone. The aortic valve, not shown in the figure, is beyond the intervalvolar trigone. Arrows SD drawn in figure 1 represent the movement of the anterior portion of the mitral annulus (and, correspondingly, of the adjacent portion of the aortic annulus) during the cardiac cycle.

With reference to figures 2 and 3, a prosthesis for mitral anuloplasty is indicated 10 in its whole. Such a prosthesis comprises an annular structure 11 composed of a flexible support segment 12 and of an intertrigonal rigid segment 13, which are connected to each other so as to form a closed ring .

The flexible support segment 12 is intended to be fixed by suture along a posterior portion PMA of the mitral annulus estending from the anterolateral trigone AT to the posteromedial trigone PT . The type of suture is not essential for the invention, provided that it is located along the whole extension of the flexible support segment 12.

The support segment 12 is flexible to such an extent that it fits, in the use, the movements of the posterior portion PMA of the mitral annulus. Moreover, it is substantially inextensible with respect to stresses transmitted in the use by the posterior portion PMA of the mitral annulus, in such a manner that it carries out an effective limitative action.

The flexible support segment 12 may consist, for example, of a body (for instance a tube) of a textile material fixed at its ends to the rigid intertrigonal segment 13, or of a structure comprising a core (for instance of metallic wire) connected at its ends to the rigid intertrigonal segment 13 and enclosed by a sheathing of textile material.

The intertrigonal rigid segment 13 interconnects the ends 12a, 12b of the flexible support segment 12, and it is adapted to act as a spacer between the anterolateral trigone AT and the posteromedial trigone PT of the mitral valve. Therefore, rigidity of the intertrigonal segment 13 must be sufficient to withstand stresses deriving from the surrounding cardiac tissue, in such a manner that the intertrigonal distance does not change in a significant manner, also in case of dilation processes of the anterior portion of the mitral annulus . For example, the intertrigonal rigid segment 13 is made of metallic material.

Preferably, the rigid intertrigonal segment 13 is bowed and it is arranged so as to project, in the use, towards the posterior portion PMA of the mitral annulus, as shown in figure 3. In other words, the intertrigonal segment 13 and the support segment 12 form in the use two arches the concavities of which are directed concordantly, according to an elevational view. This configuration allows the blood flow passing through the mitral valve to be shared out in the best manner .

In the use, the intertrigonal segment 13 is intended to be free to rotate about its pivoting points consisting of the ends 12a and 12b of the support segment 12, since the annular structure 11 of which it is part, is adapted to be fixed to the mitral annulus MA exclusively through the flexible support segment 12; in fact, the suture joining the device 10 to the mitral annulus is only applied to the flexible support segment 12, which remains therefore bound to the posterior portion of the mitral arinulus.

A sagittal section of the left ventricle LV, with the prosthesis 10 implanted in its annular position, is shown in figure 4 in a simplified manner. The left atrium and the aorta are indicated LA and A, respectively, while the aortic valve is indicated AV.

The operation of the prosthesis described above is similar to the static configuration of the double-hinged arch type. While the flexible support member 12 follows the movement of the valvular plane PV, the rigid intertrigonal segment 13 is free to swing in order to change its own tilting with respect to the valvular plane PV.

The prosthesis described above, or more precisely the rigid intertrigonal segment 13 of such a prosthesis, is adapted to act as a base for a device for correcting the mitral regurgitation, in particular the regurgitation relapse.

With reference to figures 5 to 11, a first example of a such a device consists of a clip device for valve repairing according to the Alfieri's technique. With reference in particular to figures 5 and 7, such a device has been indicated 20 in its whole. The device 20 comprises a main structure 22 having a substantially tubular shape, along which a notch 24 is formed, which allow such a device to be positioned astride the rigid intertrigonal segment 13 of the prosthesis 10. Fixing means 25 for fixing the main structure 22 of the device 20 to the rigid intertrigonal segment 13 of the prosthesis 10, are arranged inside the notch 24. In the example shown, such fixing means consist of elastically flexible pawls, so as to allow a quick engagement of the device 20 on the rigid segment 13. Preferably, the fixing means are of the releasable type, so that removal of the device is allowed in case of replacement. Moreover, the fixing means are preferably so shaped that an adjustment of the positioning in the depth of the device, with respect to the valvular plane, is allowed. In the example of the figures, a plurality of elastically flexible pawls, arranged in series along the tubular structure 22, are provided to such an effect in order to define different assembly positions for the rigid segment 13 (in the example, in particular, there are two different positions) .

Elastically foldable flaps are arranged on opposite sides of the main structure 22 of the device 20, more precisely a pair of proximal flaps 26 and a pair of distal flaps 28. Each proximal flap 26 and the corresponding distal flap 28 are urged one to the other in order to provide a closure like a folding cover. Each proximal flap 26 and the corresponding distal flap 28 are adapted to be closed on a respective leaflet of the mitrale valve, so as to make actually an anchorage .

The corrective device 20 described above can be made for example as a metallic sheathed stent.

Advantyageously, implantation of such a device is carried out by catheter. With reference to figures 6 to 11, such a transcatheter implantation procedure provides the access to the left ventricle by septostomy from right, by a catheter C inserted through the inferior vena cava IVC. Initially, the device 20 is contained in a tubular casing 30 arranged at the distal end of the catheter C. A longitudinal notch 32, corresponding to the notch 24 of the device 20, is formed on such a casing 30 in order to allow the positioning of the tubular casing 30, as well as of the device 20 contained in it, astride the intertrigonal rigid segment 13 of the prosthesis 10. Therefore, the device 20 is fixed on the segment 13 (figures 6 and 7) .

Then, the tubular casing 30 is removed from the device 20 by control means (not shown) of the catheter C, so that deployment of the distal flaps 28 is caused, in order that said flaps engage from the bottom the anterior leaflet AL and the posterior leaflet PL of the mitrale valve (figures 8 and 9) , respectively. In order to allow such an engagement to be achieved, the depth of the positioning of the device 20 will have been adjusted during the implantation step of the device into the rigid segment 13 of the prosthesis.

Continuing with driving the control means of the catheter C, the tubular casing 30 is furthermore removed from the device 20, so that also deployment of the prossimal flaps 26 is caused, in order that said flaps engage from the above the anterior leaflet AL and the posterior leaflet PL of the mitrale valve (figures 10 and 11), respectively, against the distal flaps 28. In this manner, the anterior leaflet AL and the posterior leaflet PL are anchored to the device 20, that is fixed in its turn to the rigid segment 13 of the prosthesis 10.

Therefore, the device 20 described above is substantially a clip allowing the Alfieri's technique to be carried out in the transcatheter manner, in order to correct a prolapse of the valve leaflets.

With reference to figures 12 and 13, a second example of corrective device consists of an occluding device. In the figures, such a device has been indicated 40 in its whole, and it comprises a substantially cylindrical shaped main structure 42, along which a notch 44 is formed that allows such a device to be positioned astride the intertrigonal rigid segment 13 of the prosthesis 10. Fixing means (not shown) are arranged inside the notch 24 in order to fix the main structure 42 of the device 40 to the intertrigonal rigid segment 13 of the prosthesis 10. Preferably, such fixing means are of the releasable type. Moreover, preferably, they are so shaped as to allow the positioning in depth of the device to be adjusted with respect to the valvular plane. The device 40 is so shaped that it allows the point of no valve coaptation to be occluded.

Also the corrective device 40 described above can be made like a metallic sheathed stent.

Advantageously, implantation of such a device is also carried out by catheter, analougsly with the previous embodiment. With reference to figure 13, the device 40 is positioned astride the intertrigonal rigid segment 13 of the prosthesis 10 by means of the catheter C, and it is fixed to it. In this manner, since the occluding device 40 engages at least one of the anterior and posterior leaflets AL, PL, it allow the point of no valve coaptation of the valve leaflets to be occluded.

With reference to figures 14 to 16, a third example of corrective device consists of a device combining the functions of both the devices previously described. With particular reference to figures 14 and 15, such a device has been indicated 50 in its whole. The device 50 comprises a substantially tubular shaped main structure 52, along which a notch 54 is formed that allows such a device to be arranged astride the rigid intertrigonal segment 13 of the prosthesis 10. Fixing means 55 are arranged inside the notch 54 in order to fix the main structure 52 of the device 50 to the rigid intertrigonal segment 13 of the prosthesis 10. In the example shown, such fixing means consist of elastically flexible pawls, so as to allow a quick implantation of the device 50 into the rigid segment 13. Preferably, the fixing means are of the releasable type, in order to allow the device to be removed in case of replacement. Moreover, the fixing means are preferably so shaped as to allow an adjustement of the positioning in depth of the device with respect to the valvular plane to be achieved. In the figures, to such a purpose, a plurality of pawls are arranged in series along the tubular structure 52, which define different assembly positions for the rigid segment 13 (in the example, in particular, there are two different positions) .

The main structure 52 of the device 50 is so shaped as to allow the point of no valve coaptation to be occluded.

Moreover, a pair of elastically foldable flaps 56 is arranged on opposite sides of the main structure 52 of the device 50. Such flaps 56 are urged away from the main structure 52 in order to achieve a deployed configuration, and they are adapted to engage the anterior leaflet and the posterior leaflet of the mitral valve, respectively, from the above. Also the corrective device 50 described above can be made like a sheathed metallic stent.

Advantageously, also implantation of such a device is accomplished by catheter, in a manner analogous to the previous embodiments. With reference to figures 14 to 16, the device 50 is initially contained in a tubular casing 60 arranged at the distal end of a catheter C. A longitudinal notch corresponding to the notch 54 of the device 50 is formed on such a casing 60, in order to allow the tubular casing 60, and the device 50 contained in it, to be positioned astride the intertrigonal rigid segment 13 of the prosthesis 10. The device 50 is therefore fixed on the segment 13.

The tubular casing 60 is then removed from the device 50 by control means (not shown) of the catheter C, which causes the flaps 56 to be deployed, such flaps being then positioned in order to engage the anterior leaflet AL and the posterior leaflet PL of the mitrale valve (figure 16) , respectively, from the above. In order to allow such an engagement to be achieved, the depth of positioning of the device 50 will have been adjusted during the step of implantation of the device into the rigid segment 13 of the prothesis.

The device 50 described above combines the functions of the two previous devices: it occludes the point of no valve coaptation and, moreover, it prevents the corresponding prolapse of the valve leaflets.

The implantation of a corrective device according to the invention, in a patient to whom the above described prosthesis has been previously implanted, turns out to be extremely favourable. In particular the advantages are the following :

repeatability of the corrective procedure;

low risk of mortality.

Claims

1. A device for correcting mitral regurgitation comprising a corrective structure (22, 26, 28; 42; 52, 56) for engaging at least one of the leaflets (AL, PL) of the mitral valve, characterized in that said corrective structure is provided with fixing means (25; 55) for fixing said corrective structure to a base, in which said base is provided with a prosthesis (10) for mitral annuloplasty comprising an annular structure (11) composed of a flexible support segment (12), which is adapted to be sutured along a posterior portion (PMA) of the mitral annulus (MA) extending from the anterolateral trigone (AT) to the posteromedial trigone (PT) , and of a rigid intertrigonal segment (13) interconnecting the ends (12a, 12b) of the flexible support segment, said rigid intertrigonal segment being adapted to act as a spacer between said anterolateral trigone and posteromedial trigone, in which said annular structure is adapted to be fixed to the mitral annulus exclusively through the flexible support segment, and in which said base for the corrective structure consists of the rigid intertrigonal segment of the prosthesis .

2. A device according to claim 1, in which said fixing means are arranged for releasably fixing said corrective structure to said rigid intertrigonal segment of the prosthesis .

3. A device according to claim 1 or 2, in which said fixing means are arranged so that the corrective structure can be positioned in a manner adjustable in the depth with respect to the valve plane.

4. A device according to any one of the preceding claim, in which said corrective structure is elongate-shaped and has a notch (24; 44; 54) extending therealong, said notch allowing said corrective structure to be arranged astride the rigid intertrigonal segment of the prosthesis, in which said fixing means are formed within said notch.

5. A device according to claim 4, in which said fixing means comprise elastically flexible pawls for engaging the rigid intertrigonal segment of the prosthesis.

6. A device according to any one of the preceding claims, said device being constituted by an occluding device adapted to occlude a no-coaptation point of the valve leaflets.

7. A device according to any one of the preceding claims, in which said corrective structure is provided with deployable flaps (26, 28; 56) for engaging the valve leaflets .

8. A device according to claim 7, said device being constituted by a clip for valve repairing according to the Alfieri's technique.

9. A kit for correcting mitral regurgitation, including: a prosthesis (10) for mitral annuloplasty comprising an annular structure (11) composed of a flexible support segment (12) , which is adapted to be sutured along a posterior portion (PMA) of the mitral annulus (MA) extending from the anterolateral trigone (AT) to the posteromedial trigone (PT) , and of a rigid intertrigonal segment (13) interconnecting the ends (12a, 12b) of the flexible support segment, said rigid intertrigonal segment being adapted to act as a spacer between said anterolateral trigone and posteromedial trigone, in which said annular structure is adapted to be fixed to the mitral annulus exclusively through the flexible support segment; and

a device (20; 40; 50) for correcting mitral regurgitation, comprising a corrective structure (22, 26, 28; 42; 52, 56) for engaging at least one of the leaflets (AL, PL) of the mitral valve, in which said corrective structure is provided with fixing means (25; 55) for fixing said corrective structure to a base, said base being constituted by the rigid intertrigonal segment (13) of the prosthesis.