IMPLANT FOR IMPROVING COAPTATION OF AN ATRIOVENTRICULAR VALVE

Abstract

An implant for improving coaptation of an atrioventricular valve in a heart, the atrioventricular valve having a native first leaflet, a native second leaflet and optionally an annulus adjacent a wall of an atrium of the heart, the implant comprising an artificial leaflet to replace or support the first and/or second native leaflets, fixing means for fixing the implant to the annulus or to the first and/or second native leaflets and retention means for preventing prolapse of the artificial leaflet. The retention means comprise or consist of a backbone element extending along the artificial leaflet and towards a distal end of the artificial leaflet and being connected to the artificial leaflet at at least two attachment points, wherein the backbone element is configured to be bendable between first and second states of bending and wherein limiting means are provided for limiting the degree of bending.

Claims

1-17. (canceled)

18. An implant for improving coaptation of an atrioventricular valve in a heart, the atrioventricular valve having a native first leaflet, a native second leaflet and optionally an annulus adjacent a wall of an atrium of the heart, the implant comprising: an artificial leaflet configured to one of replace and support at least one of the first and second native leaflets; fixing means for fixing the implant to one of the annulus and the at least one of the first and second native leaflets; and retention means for preventing prolapse of the artificial leaflet; wherein the retention means one of comprise and consist of a backbone element extending along the artificial leaflet and towards a distal end of the artificial leaflet and being connected to the artificial leaflet at at least two attachment points; wherein the backbone element is configured to be bendable between a first state of bending and a second state of bending; and wherein limiting means are provided for limiting the degree of bending.

19. The implant according to claim 18, wherein the backbone element comprises a plurality of segments, pivotably connected to each other.

20. The implant according to claim 19, wherein the limiting means comprise an abutment element on each segment for limiting the pivoting angle of one segment relative to an adjacent segment.

21. The implant according to claim 18, wherein the implant comprises a resting element fixed to the proximal end of the backbone element and configured to rest against the wall of the atrium adjacent the valve.

22. The implant according to claim 21, wherein the resting element comprises a support element aligned with the backbone element and configured to rest against the wall of the atrium adjacent the valve.

23. The implant according to claim 18, wherein the artificial leaflet comprises one of a mesh, a flexible net, a plurality of flexible wires, a plurality of yarns, a fabric, and a sheet.

24. The implant according to claim 23, wherein: the artificial leaflet comprises the sheet; and the sheet comprises one of a PTFE sheet and a PTFE matrix.

25. The implant according to claim 18, wherein the artificial leaflet comprises a wire frame extending along a periphery of the artificial leaflet.

26. The implant according to claim 25, wherein the wire frame is connected to at least two ribs extending perpendicularly from the backbone element.

27. The implant according to claim 18, wherein the side of the artificial leaflet, which faces towards the atrium, has an anticoagulant surface and the side of the artificial leaflet, which faces towards the first or second native leaflet, has a porous surface.

28. The implant according to claim 18, wherein the backbone element is covered by a sheath.

29. The implant according to claim 18, wherein a distal end section of the backbone element comprises a u-bend to clamp a distal region of one of the first and second native leaflets between segments of the backbone element.

30. The implant according to claim 29, wherein spring means are arranged between segments arranged in the distal end section of the backbone element, to resiliently press segments of the backbone element against the distal region of the one of first and second native leaflets.

31. The implant according to claim 18, wherein: the fixing means are arranged in the proximal end region of the artificial leaflet; the fixing means comprise a central needle unit configured to penetrate one of the annulus and the at least one of the first and second native leaflets in a penetration region, and a stabilization platform having an abutment surface for abutting the penetration region; and the central needle unit and the stabilization platform are movably arranged in a housing in an axial direction of the needle.

32. The implant according to claim 31, wherein the fixing means are aligned with the backbone element.

33. The implant according to claim 31, wherein the fixing means comprise first spring means acting on the needle unit for displacing the needle unit relative to the housing and second spring means acting on the stabilization platform for displacing the stabilization platform relative to the housing.

34. The implant according to claim 33, wherein the fixing means further comprises a first releasable locking means to hold the central needle unit in a spring-loaded position and a second releasable locking means to hold the stabilization platform in a spring-loaded position.

35. The implant according to claim 31, wherein: the central needle unit comprises anchoring elements on its distal end; and the anchoring elements are movable relative to the central needle unit between a first position, in which the anchoring elements are positioned against a needle shaft, and a second position, in which the anchoring elements are tilted away from the needle shaft.

36. The implant according to claim 21, wherein the artificial leaflet and the resting element are deployable from a first position, in which the artificial leaflet and the resting element are folded for being arranged within a tubular housing of a delivery device, into a second position, in which the artificial leaflet and the resting element are deployed.

37. The implant according to claim 18, wherein the implant further comprises an annuloplasty device comprising at least a first and a second anchor unit, that are deployable to the mitral valve by means of a vascular delivery device, such as a catheter, and positionable in a row along the annulus, comprising anchor means arranged on each of the first and second anchor units, whereby the anchor units are arranged to be movable towards one another, so that the anchor means engage with the annulus thereby pulling the annulus together when the first and second anchor units are moved.

38. The implant according to claim 37, wherein the annuloplasty device comprises more than two anchor units.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In the following the present invention will be described by reference to some exemplary embodiments.

[0061] FIG. 1 is an isometric view of a first embodiment of the implant according to the invention,

[0062] FIG. 2 is a cross sectional view of the first embodiment of the implant as depicted in FIG. 1,

[0063] FIG. 3 is a cross sectional view of a second embodiment of the implant according to the invention,

[0064] FIG. 4a shows a cross sectional view of the fixing means of the implant according to the invention before deployment,

[0065] FIG. 4b shows a cross sectional view of the fixing means of FIG. 4a after deployment,

[0066] FIG. 5a shows a cross sectional view of the implant as depicted in FIG. 1 and FIG. 2 when being fixed to the posterior leaflet of the mitral valve during atrial systole,

[0067] FIG. 5b shows a cross sectional view of the implant as depicted in FIG. 5a during ventricular systole,

[0068] FIG. 6 shows an isometric view of a third embodiment of the implant according to the invention when being combined with an annuloplasty device,

[0069] FIG. 7a shows a sectional view of the backbone element according to a first embodiment of the invention,

[0070] FIG. 7b shows an isometric view of one segment of the backbone element as depicted in FIG. 7a,

[0071] FIG. 7c shows a sectional view of the segment as depicted in FIG. 7b, and

[0072] FIG. 8 shows a cross-sectional view of a fourth embodiment of the invention.

DETAILED DESCRIPTION

[0073] FIG. 1 and FIG. 2 show a first embodiment of the implant according to the invention. The implant comprises an artificial leaflet 1, a support element 2, fixing means 3 and retention means. The artificial leaflet comprises a mesh or a sheet 6. The retention means comprise a backbone element 4. Further, a plurality of ribs 5 extending perpendicularly from the backbone element 4, and a wire frame 7 extending along a periphery of the artificial leaflet 1 are provided. The backbone element 4 may be perforated at certain intervals for arranging the ribs 5.

[0074] The backbone element 4 extends along the artificial leaflet 1 and towards its distal end 8 and is connected to the artificial leaflet 1 at least at attachment points 9 and 10. Attachment point 9 is located on the distal end 8 of the artificial leaflet 1 and attachment point 10 is located on the proximal end 11 of the artificial leaflet 1.

[0075] The backbone element 4 comprises a plurality of segments 12, which are pivotably connected to each other, whereby abutment elements 13 are provided on the distal ends of each of the segments 12 for limiting the pivoting angle of one segment relative to the adjacent segment.

[0076] The backbone element 4 and the segments 12 thereof are shown in more detail in FIG. 7a-c. The segments 12 each comprise an abutment element 13 that extends from one end of the segment 12. The segment comprises a pivoting axis 35 on both ends thereof for pivotably being connected to an adjacent segment 12. The abutment element 13 comprises an abutment surface 36 that defines the maximal pivoting angle relative to the adjacent segment 12. In other words, the angular extension or inclination 34 of the abutment surface 36 limits the pivoting angle of one segment relative to the adjacent segment 12.

[0077] FIG. 3 shows a cross sectional view of a second embodiment of the implant according to the invention, which essentially corresponds to the first embodiment as depicted in FIG. 1 and FIG. 2, but comprises a u-bend in the distal end section 8 of the backbone element 4, which enables clamping of a distal region of the dysfunctional native leaflet between the segments 12 of the distal end section 8 of the backbone element 4.

[0078] FIG. 4a shows a cross sectional view of the fixing means of the implant according to the invention before deployment, and FIG. 4b shows a cross sectional view of the fixing means of FIG. 4a after deployment.

[0079] FIG. 4a shows that the fixing means 3 comprises a central needle unit 14 and a stabilization platform 15 having an abutment surface 16. The central needle unit 14 and the stabilization platform 15 are arranged in a housing 17 and both moveable in an axial direction according to arrow 18.

[0080] For causing said axial movement, the fixing means 3 comprises first spring means 19 acting on the needle unit 14 and second spring means 20 acting on the stabilization platform 15.

[0081] The fixing means 3 further comprises a first releasable locking means 21 to hold the central needle unit 14 in the spring-loaded position, whereby the spring-load is exerted by the first spring means 19, and a second releasable locking means 22 to hold the stabilization platform 15 in a spring-loaded position, whereby the spring-load is exerted by the second spring means 20.

[0082] Further, the central needle unit 14 comprises anchoring elements 23 on its distal end, which are covered by a protecting means 24, which covers the anchoring elements 23 when the tip of the central needle unit 14 is in the needle guide 25.

[0083] When the first locking means 21 is released by being pulled out of the housing 17, the first spring means 19 causes the central needle unit 14 to move according to arrow 18. During said movement the central needle unit 14 is pushed out of the needle guide 25 and the anchoring elements 23 as well as the protecting means 24 of the central needle unit 14 deploy as shown in FIG. 4b.

[0084] The anchoring elements 23 and the protecting means 24 are movable relative to the central needle unit 14 between a first, undeployed position as shown in FIG. 4a, in which the anchoring elements 23 and the protecting means 24 are positioned against the needle shaft 25, and a second, deployed position as shown in FIG. 4b, in which the anchoring elements 23 and the protecting means 24 are tilted away from the needle shaft 25.

[0085] When the second locking means 22 is released by being pulled out of the housing 17, the second spring means 20 causes the stabilization platform 15 to move according to arrow 18 towards the deployed anchoring elements 23 so as to clamp the leaflet tissue that is arranged between the abutment surface 16 and the anchoring elements 23.

[0086] FIG. 5a shows a cross sectional view of the implant according to the first embodiment of the invention as depicted in FIG. 1 and FIG. 2 being fixed to the posterior native leaflet 26 of the mitral valve, wherein the mitral valve is in its open position. Therefore the posterior leaflet 26 and the anterior leaflet 27 are in an open position, which allows blood flow from the left atrium 28 into the left ventricle 29.

[0087] The fixing means 3 is fixed to the annular region of the posterior leaflet 26 and the support element 2, which is aligned with the backbone element 4 of the artificial leaflet 1 rests against the wall of the left atrium 28 in order to resist to the tilting forces acting upon the artificial leaflet 1, which are caused by the dynamic pressure changes prevailing within the left ventricle 29.

[0088] FIG. 5b shows a cross sectional view of the implant as depicted in FIG. 5a during ventricular systole, i.e. when the posterior leaflet 26 and the anterior leaflet 27 are in a closed position, whereby the blood flow from the left atrium 28 into the left ventricle 29 is blocked. The degree of bending of the individual segments 12 of the backbone element 4 is higher in its middle section and lower at its proximal end 11 and at its distal end 8, whereby proper valve closure is allowed and prolapse of the artificial leaflet is prevented.

[0089] When being fixed to the annulus of the posterior leaflet 26 the central needle unit 14 has penetrated the annulus, whereby the anchoring elements 23 are arranged facing the lower surface of the posterior leaflet 26 and the abutment surface 15 of the stabilization platform 15 is arranged on the upper surface of the posterior leaflet 26 and abuts the penetration region to press the anchoring elements 23 towards the abutment surface 15 and to enable an anchoring effect on the lower side of the leaflet 26.

[0090] FIG. 6 shows an isometric view of a third embodiment of the implant according to the invention when being combined with an annuloplasty device 30.

[0091] The annuloplasty device 30 and the artificial leaflet 1 are connected in the proximal region 11 of the artificial leaflet 1. The annuloplasty device 30 comprises a plurality of anchor units 31 with anchor means 32 being arranged on each of said anchor units 31.

[0092] When the combined implant as depicted in FIG. 6 is fixed to the posterior leaflet 26 of the mitral valve the anchor units 31 are positioned in a row along the curvature of the annulus, whereby the anchor means 32 engage with the annulus when the anchor units 31 are moved according to arrow 33 thereby pulling the annulus together.

[0093] FIG. 8 shows a cross-sectional view of a fourth embodiment according to the invention, in which the distal end section 8 of the backbone element 4 comprises a u-bend, which encloses the distal region of the dysfunctional native leaflet 26 and the backbone element 4 further extends towards the lower side of the annulus, i.e. towards the region where the central needle unit 14 has penetrated the native leaflet 26. Thereby full coverage of the dysfunctional leaflet 26 is achieved, i.e. the leaflet 26 is covered by the backbone element 4 on its upper as well as its lower surface.