Device and method for improving function of heart valve

Abstract

A device for improving the function of a heart valve comprises a first loop-shaped support, which is configured to abut a first side of the heart valve, and a first flange unit being connected to said first loop-shaped support. The flange unit is configured to be arranged against said annulus when said first loop-shaped support is abutting said heart valve.

Claims

1. A system comprising a medical device comprising: a first loop-shaped support, which is configured to abut a first side of a native heart valve, a second loop-shaped support, which is configured to abut a second side of the native heart valve opposite to said first side, wherein an end of the second loop-shaped support is configured to be inserted through a natural opening of the heart valve formed between leaflets at a commissure of the leaflets, wherein the first loop-shaped support is continuous with the second loop-shaped support to form a coil-shaped body configured to be rotated into place so that a portion of native heart valve tissue is trapped between the first and second loop-shaped supports, a heart valve prosthesis adapted to be carried by the first loop-shaped support or the second loop-shaped support when the first and second loop-shaped supports are positioned in abutment with the native heart valve, wherein the medical device comprises a flange an integral flame unit extending radially outward from at least one of the first and second loop-shaped supports, wherein the flange unit is adapted to provide a sealing surface against an annulus of the native heart valve when the first and second loop-shaped supports are positioned in abutment with the native heart valve.

2. System according to claim 1, wherein the heart valve prosthesis is adapted to be arranged on the first loop-shaped support or on the second loop-shaped support.

3. System according to claim 1, wherein the heart valve prosthesis is adapted to be attached to the flange unit.

4. System according to claim 1, wherein the flange unit is adapted to form a connection of at least one of the loop-shaped supports and the heart valve prosthesis against an annulus of the native heart valve.

5. System according to claim 1, wherein the flange unit is connected to the first loop-shaped support and/or the second loop shaped support.

6. System according to claim 1, wherein the flange unit flange unit comprises barb elements for affixing the medical device to tissue.

7. System according to claim 1, wherein the first loop-shaped support is adapted to abut an atrial side of the native heart valve and the second loop-shaped support is adapted to abut a ventricular side of the native heart valve, wherein an outer boundary of the second loop-shaped support is greater than an outer boundary of the first loop-shaped support.

8. System according to claim 1, wherein the second loop-shaped support is displaced radially with respect to the first loop-shaped support.

9. System according to claim 1, wherein said end of the second loop-shaped support have a greater pitch than the rest of the coil-shaped body.

10. System according to claim 1, wherein the medical device comprises a shape memory material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) These and other aspects, features and advantages of which embodiments of the invention are capable of will be apparent and elucidated from the following description of embodiments of the present invention, reference being made to the accompanying drawings, in which

(2) FIG. 1 schematically illustrates a patient with a heart shown in cross-section and a device of an embodiment of the present invention schematically illustrated as supporting the mitral valve;

(3) FIG. 1A is a cross-sectional view of the left ventricle showing the mitral valve in perspective;

(4) FIG. 2 is a perspective view of a body of a device according to a first embodiment of the invention;

(5) FIG. 3 is a cross-sectional view of the body in FIG. 2;

(6) FIG. 4 is a perspective view of the first embodiment of the device comprising the body shown in FIG. 2;

(7) FIG. 5 is a cross-sectional view of the device in FIG. 4;

(8) FIG. 6 is a perspective view of a second embodiment of the device;

(9) FIG. 7 is a perspective view of a third embodiment of the device;

(10) FIG. 8 is a perspective view of a fourth embodiment of the device;

(11) FIG. 9a, 9b are perspective views that illustrate insertion of an embodiment of the device;

(12) FIG. 10 is a cross-sectional view showing an embodiment of the device inserted in a heart valve;

(13) FIGS. 11 and 12 are schematic illustrations that show a heart valve before and after remodeling by using the device;

(14) FIG. 13 is a cross sectional view that shows the device fixed to the annulus;

(15) FIG. 14a is a cross sectional view that shows a first embodiment of the device comprising an artificial prosthetic heart valve;

(16) FIG. 14b is a cross sectional view that shows a second embodiment of the device comprising an artificial valve;

(17) FIG. 15 is a cross-sectional view of an alternative device having one loop-shaped support carrying the flange unit;

(18) FIG. 16a, 16b are cross sectional views of embodiments involving a shape change; and

(19) FIG. 17 is a cross sectional view schematically illustrating a flange unit having barb elements for affixing to tissue.

DESCRIPTION OF EMBODIMENTS

(20) Specific embodiments of the invention will now be described with reference to the accompanying drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. The terminology used in the detailed description of the embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, like numbers refer to like elements.

(21) FIG. 1 illustrates a patient 10 having a heart 12 shown in cross-section including a left ventricle 14 and a right ventricle 16. The concepts of the present invention are suitable to be applied, for example, to a mitral valve 18 which supplies blood into left ventricle 14. Mitral valve 18, as better shown in FIG. 1A, includes an annulus 20 and a pair of leaflets 22, 24 which selectively allow and prevent blood flow into left ventricle 14. It will be appreciated that the term valve tissue is used extensively throughout this disclosure in reference to the drawings. The inventive principles are equally applicable when referring to any valve tissue such as annulus tissue, leaflet tissue or other attached vessel tissue. Leaflets 22, 24 are supported for coaptation by chordae tendinae or chords 26, 28 extending upwardly from respective papillary muscles 30, 32. Blood enters left ventricle 14 through mitral valve 18 and is expelled during subsequent contraction of heart 12 through aortic valve 34. It will be appreciated that the present invention is applicable to tricuspidal heart valves as well.

(22) A body 41 comprised in a device 40 according to a first embodiment of the present invention is shown in FIGS. 2 and 3. The body 41 comprises a first and a second loop-shaped support 42, 44.

(23) As used herein, the term “loop-shaped” should be construed as a curved shape that may be closed, as at least a part of a ring with e.g. a circular, elliptic, or D-shaped form or any other closed form which may fit the shape of the valve annulus. The term “loop-shaped” also includes a curved shape that is open forming an arcuate shape, such as a C-shape or U-shape, which includes an angular turn of at least 180° such that the support may abut valve tissue along a major part of the annular valve shape. The term “loop-shaped” also includes a curved shape overlapping itself to form a portion of a coil.

(24) The term “loop-shaped” also includes three dimensional curves as mentioned in the previous paragraph.

(25) The loop shape of at least a part of at least one of the supports 42, 44 may also in some embodiments be patient configured. The shape may be designed specifically to an anatomy of a patient. The patient specific loop shape may be virtually derived from 3D patient data, e.g. acquired by image modalities, such as Magnetic Resonance (MR) or Computer Tomography (CT) Imaging.

(26) In U.S. Pat. Nos. 6,419,696, 6,730,121, 6,964,684, and WO 2006/091163, which are assigned to the same applicant as the present invention and incorporated by reference herein in their entirety for all purposes, devices are disclosed for repairing and replacing a heart valve in various embodiments. The devices include at least first and second support rings connected together in loop-shaped configurations to abut opposite sides of a valve annulus. A replacement valve may be secured to the loop-shaped devices.

(27) The first support 42 may be continuous and/or integral with the second support 44 such that the supports 42, 44 assume a coiled configuration in the form of a spiral or keyring-type configuration with two loops.

(28) The second support 44 may have an outer boundary or extent which is greater in relation to the outer boundary of the first support 42. The supports 42, 44 may in an embodiment have corresponding shapes with the second support 44 being in larger scale than the first support 42. This is advantageous in creating a pinch of the valve tissue between the first 42 and second supports 44.

(29) An end 45 of the second support 44, which will lead the coil during insertion of the device at the valve, may in an embodiment have a greater pitch than the rest of the coil. This implies that the leading end 45 of the coil during rotation into position in the valve will project from immediate contact with the valve tissue and, therefore, the risk that the coil is caught by the chords is diminished.

(30) The body 41 is shown in cross-section in FIG. 3. The body 41 has in an embodiment at least partly a round cross-sectional shape. In other embodiments, the cross section of the body 41 may be substantially flat, oval, flattened and/or have flattened edges.

(31) In embodiments, the opposed surfaces 46 thus provide a pinch to trap valve tissue there between. A round cross-section is also advantageous in creating a pinch of the valve tissue which will not harm the leaflets in their movement during normal heart action.

(32) The second loop-shaped support 44 is slightly displaced radially with respect to the first loop-shaped support 42. This implies that the first and second loop-shaped supports 42, 44 are not arranged directly on top of each other in some embodiments. The pinch between the first 42 and second supports 44 is therefore not sharply defined in a radial direction of the valve. This implies that a pinching force between the supports is not focused to a specific radial position of the valve. As a result, the pinching force does not affect the movement of the leaflets during normal heart action and there is a diminished risk of rupture in the leaflets at the pinch.

(33) The supports may in some embodiments be interrelated in such manner that the outer boundary of the first support 42 has a diameter corresponding to a line through the centre of the second support 44. Thus, the supports 42, 44 may overlap somewhat such that tissue is not allowed to move through the pinch and the shape of the valve is maintained advantageously.

(34) Further, the cross-section of the supports 42, 44 is substantially round, which also gives a soft contact between the supports and the valve tissue to further diminish the risk of rupture in the leaflets.

(35) The body 41 may be formed from a core of a rigid material, such as a metal, e.g., titanium, or plastic. Any suitable medical grade material(s) may be used.

(36) The rigid material may provide a passive spring function such that the loops of the coil may be forced a small distance away from each other but will flex back towards each other when the force is released. The core of the body 41 may be coated by a softer layer, such as a textile.

(37) The body 41 may alternatively be formed from a shape memory material. The body 41 will then assume a desired, programmed shape, when e.g. heated to a specific temperature. This allows the body 41 to be compressed or straightened of the form better suited for delivering during insertion and to assume a spiral shape when inserted at the heart valve. Also, the flange unit may be made of such a shape memory material, e.g. to provide a first, delivery shape and a second, delivered shape thereof.

(38) Now turning to FIGS. 4 and 5, a first embodiment of the medical device 40 is disclosed. The device 40 comprises a body 41 in accordance with that described above with reference to FIGS. 2 and 3, whereby the body 41 as such is not further discussed.

(39) The device 40 comprises a flange unit 50 being connected to the body 41 and more precisely to the first loop-shaped support 42. The flange unit 50 has in an embodiment a continuous extension along the periphery of the first loop-shaped support 42.

(40) In some embodiments, the flange unit 50 may be integral with at least a portion of the body 41, as e.g. shown in FIG. 16a.

(41) In some embodiments the flange unit 50 is made of a tube shaped flexible material 52 being passed onto the first loop-shaped support 42, whereby a loose substantially co-axial connection between the loop-shaped support and the flange unit is achieved. The connection may also be fixed or rigid. The flexible material may by way of example be a fabric or woven structure made of Polyethylene (PE) or polytetrafluoroethylene (PTFE). A fabric has the advantage that it presents a rough, holed or porous surface enhancing growth of and overgrowth of endothelia. Further, a fabric is easily penetrated by sutures or clips. In addition, the flexible material admits the flange unit 50 to be conformed to the annulus.

(42) The flange unit 50 does in the disclosed embodiment form a flange surface 54 extending downwards out from the body. More precisely the flange unit 50 forms in some embodiments and angle a to a horizontal, diametric plane formed by the first loop-shaped support. The angle a is approximately between 30-60°, such as 40-50° to the diametric plane. Such angle improves the visibility during insertion of the device. In some embodiments, improved visibility may be provided during insertion of the device, whereupon the flange unit 50 changes shape to a position facilitating fixation thereof to surrounding tissue. Thus, medical procedures for heart valve repair and/or replacement may be speeded up considerably.

(43) In a practical embodiment the flange surface 54 has a width in the range of approximately 2-4 mm such as 2.5-3.5 mm. The width of the flange radially outwards allows an indication for the surgeon of the area in which sutures or clips should be positioned when fixating the device to the annulus. This is further discussed below with reference to FIG. 13.

(44) Initially, before inserted into the heart valve, the flange surface 54 extends downwardly. When positioned in the atrial side of the heart valve, the device will be arranged abutting the annulus whereby the flange unit will be conformed to the annulus, changing its angle from extending downwardly to extending upwardly. This ability to conform is a combination of the flexibility of the (fabric) material and the width of the flange means.

(45) On its outer periphery, the flange unit 50 may comprise a reinforcing element 65, which is schematically illustrated in FIG. 4. Such reinforcing element may by way of example have the form of a thread 65a or a bead 65b.

(46) Now turning to FIG. 6, a second embodiment of the device 40 is disclosed. The device differs from that disclosed in FIGS. 4 and 5 in that the flange unit 50 extends from the first loop-shaped support 42 to the second loop-shaped support 44. The flange unit 50 may be formed in one piece or be separated into a first and a second piece, wherein the first piece is connected to the first loop-shaped support and the second piece is connected to the second loop-shaped support. The connection may be a rigid connection or a loose connection. The latter may be achieved by the flange unit being passed onto the loop-shaped support(s).

(47) The flange unit may be continuous or intermittent along its extension.

(48) The second embodiment is suitable no matter if the device is to be used for repairing or replacing a valve.

(49) Now turning to FIG. 7, a third embodiment of the device 40 is disclosed. The device 40 differs from that disclosed in FIGS. 4 and 5 in that the flange unit 50 extends along the second loop-shaped support 44. When positioned in the heart valve, the second loop-shaped support 44 is intended to abut the ventricle side of the heart valve, whereas the first loop-shaped support 42 is intended to abut the atrial side. The flange unit 50 may be continuous or intermittent along its extension. The third embodiment may be suitable when used in valve replacement. An artificial, i.e. prosthetic valve may be carried by either the body or the flange means.

(50) Now turning to FIG. 8, a fourth embodiment of the device 40 is disclosed. The device 40 differs from that disclosed in FIGS. 4 and 5 in that the flange unit 50 extends along the second loop-shaped support 44 and forms two flange surfaces 54, both being connected to the second loop-shaped support 44. The flange surfaces 54 are so arranged on the loop-shaped support 44 that they overlap the commissures when the device is arranged in the heart valve abutting the annulus. Thereby the two flange surfaces form a sealing preventing possible leakage of blood from the ventricle side to the atrial side.

(51) In the above discussed embodiments of the device, the flange unit has been disclosed as being either continuous or intermittent along its extension. The flange unit may further have a non-uniform width varying along its extension. By way of example the width may be larger in a region corresponding to a position overlapping the commissure when the device is arranged in the heart valve abutting the annulus.

(52) Referring now to FIGS. 9-11, a method for repairing a heart valve by means of the device according to the first embodiment will be described.

(53) First, access to the heart valve is achieved by conventional techniques, including arresting the heart and opening the chest. Alternatively, an intraluminal catheter based delivery technique may be applied. In FIG. 9a, the device 40 is shown when being inserted to the mitral valve 18 from the atrial side. The device 40 is being carried on a carrier or tool (not shown), which is connected to a stem for remote control of the positioning of the carrier. An end 56 of the second loop-shaped support 44 is brought to the opening of the mitral valve 18 at a commissure 60 between the leaflets 22, 24, as shown in FIG. 9b. The end 56 is led through the opening and the carrier is turned 360 degrees. Thus, the second support 44 will be rotated into place on one side of the valve 18, whereas the first support 42 and the flange unit is placed on the opposite side of the valve 18. During this rotational movement the flange unit 50 is deflected from its original direction forming an angle of 30-60° downwards from the diametric plane formed by the support 42 to a direction extending in an angle upwards from the diametric plane corresponding to the wall formed by the annulus 20. The deflection allowed by the flexibility of the flange unit 50 results in a close abutment between the flange unit 50 and the atrial side of the annulus 20. If necessary, the flange unit 50 may be additionally conformed to the annulus 20. In this way, the device 40 is arranged in engagement with the valve 18, as shown in FIG. 10.

(54) Further, the supports 42, 44 are placed on opposite sides of the valve 18 pinching valve tissue between them to maintain a shape of the valve 18. The leaflets 22, 24 may now be drawn towards each other through the pinch of the support rings 42, 44 so as to remodel the shape of the valve 18. The leaflets may be drawn through the pinch by means of a forceps instrument. The supports 42, 44 may flex away from each other to allow drawing leaflets 22, 24 through the pinch and towards each other for preventing the leaflets 22, 24 to slip back. The valve annulus 20 may in this way be remodeled and the new shape is maintained by the supports 42, 44, see FIGS. 11 and 12 showing before and after remodeling. In FIG. 11 a defective closure region 400 of the valve leaflets 22, 24 is shown. The supports 42, 44 may have roughened, opposed surfaces 46 to better keep the leaflets 22, 24 from slipping through the pinch and to hold the valve annulus 20 in its reshaped form.

(55) The device 40 may now be secured to the valve 18 for strengthening the fixation of the relative position between the supports 42, 44 and the valve tissue, see FIG. 13. The fixation may be made by clips or sutures 62 which are arranged through the flange unit 50 and its circumferential flange surface 54. By the latter being made of fabric it is easily penetrated. The clips or sutures 62 are preferably oriented and positioned in the circumferential direction of the flange unit 50. The number of fixation points is arbitrary for the provision of a durable fixation.

(56) The flange unit 50 provides in some embodiments a better seat and prevents sliding of the device 40. Thus, the device 40 is positioned more stable in the procedure, which is advantageous, especially for long-term performance of the device after insertion.

(57) As illustrated in FIG. 10, the second support 44 is slightly displaced radially with respect to the first support 42. This implies that the first and second supports 42, 44 are not arranged directly on top of each other. The pinch between the first and second supports is therefore not sharply defined in a radial direction of the valve. This implies that a pinching force between the supports is not focused to a specific radial position of the valve. As a result, the pinching force does not affect the movement of the leaflets during normal heart action and there is a diminished risk of rupture in the leaflets at the pinch. The supports are interrelated in such manner that the outer boundary of the first support 42 has a diameter corresponding to a line through the centre of the second support 44. Thus, the supports 42, 44 overlap somewhat such that tissue is not allowed to move through the pinch and the shape of the valve is maintained. Further, the cross-section of the supports 42, 44 is round, which also gives a soft contact between the supports and the valve tissue to further diminish the risk of rupture in the leaflets.

(58) The method described above is applicable no matter the shape, position or extension of the flange means. Further, the method is applicable no matter if the device is inserted from the atrial side or the ventricle side.

(59) A device having a flange unit on the first, upper loop-shaped support is suitable when the device is to be positioned on the atrial side, providing a fixation surface to the atrial side of the annulus. Such device is also suitable when carrying an artificial valve. Further, a device having a flange unit on the second loop-shaped support is suitable when the second loop-shaped support is to be positioned on the ventricle side of the heart valve.

(60) A device having a flange unit extending from the first to the second loop-shaped support is suitable no matter if the device is positioned on the atrial side or the ventricle side of the heart valve.

(61) With reference to FIG. 14a and FIG. 14b, it is to be understood that the device may be used for replacement of heart valves as well. For that purpose the device 40 comprises in addition to a body 41 and a flange unit 50 an artificial valve 64. The flange unit 50 may be carried by the first loop shaped support 42 as is shown in FIG. 14a. Alternatively, as is shown in FIG. 14b, the flange unit 50 may extend from the first 42 to the second 44 support. Although not shown, it is to be understood that each support 42, 44 may carry its own flange unit 50, or that the flange unit may be carried by the second support 44 only.

(62) The method of inserting, positioning and fixation of the device is generally the same as that used when repairing a heart valve, whereby the method as such is not further discussed.

(63) It should be emphasized that the preferred embodiments described herein are in no way limiting and that many alternative embodiments are possible within the scope of protection defined by the appended claims.

(64) By way of example, the device 40 and its body 41 has been disclosed as having a first 42 and a second 44 loop-shaped support. The device 40 is applicable with only one loop-shaped support carrying the flange unit 50. One such embodiment is disclosed in FIG. 15.

(65) Further, the access to the heart valve may be achieved endoscopically, or transluminally, catheter based. In such case, the device 40 needs to be inserted through a narrow tube (endoscope or catheter). This implies that the device 40 will need to be compressed during insertion in order to pass through the endoscope or catheter. The device 40 needs to assume its proper shape after having been passed through the endoscope. Therefore, using an endoscopic or catheter based approach, the body may advantageously be formed from a shape memory material. This allows the device 40 to be compressed and also to have a stable shape when being applied to the heart valve. In the alternative, where the access to the heart valve may be achieved through a catheter, which is passed through the vascular system to the heart. In this case, the supports may be formed from a shape-memory material, which during insertion extends along the catheter in a flexible state and, when pushed out of the catheter at the heart valve, assumes a pre-stressed coil-shape in order to abut the heart valve on opposite sides.

(66) The first and second loop-shaped supports may be connected to each other by means of a connecting part so as to form a coil-shape. The coil-shape of the device is advantageous during insertion, since the device may then be rotated into position, as described above. However, the connecting part is detachable from at least one of the supports. Thus, when the device has been inserted, the connecting part may be detached and removed from the opening of the valve.

(67) The loop-shaped support(s) and the flange unit may be provided as separate parts.

(68) Further, it is to be understood that the flange means, or at least a wing part thereof, may form an arbitrary angle to its corresponding loop-shaped support.

(69) FIG. 16a, 16b are cross sectional views of embodiments involving a shape change.

(70) In FIG. 16a the change of shape of a flange unit 50 is illustrated, e.g. for being out of a line of sight for a surgeon during insertion (dotted line) and, when in contact with body tissue, turning to a second shape (continuous line) for attaching to the tissue.

(71) In FIG. 16a the change of shape of a flange unit 50 is illustrated in two steps or directions. Firstly the flange unit may shrink in a first direction, in order to eliminate any wrinkles or folds therein. Subsequently or concurrently, the flange unit 50 may change shape in a second direction, e.g. as described with reference to FIG. 16a.

(72) FIG. 17 is a cross sectional view schematically illustrating a flange unit 50 having barb elements 500 for affixing the device 40 to tissue. The flange unit 50 may thus be a carrier for fixation elements. The flange unit 50 may thus be inserted into the body more effectively.

(73) In some embodiments, different materials may be used for parts of the device 40. For instance, the inner rings 42, 44 may be made of a stiffer more stable than a more flexible outer part, e.g. the flange unit 50.

(74) While several embodiments of the present invention have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the functions and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the present invention. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teachings of the present invention is/are used.

(75) Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, the invention may be practiced otherwise than as specifically described and claimed. The present invention is directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the scope of the present invention as limited by the appended patent claims.