METHOD OF IMPLANTING VALVE PROSTHESIS HAVING ATRIAL ANCHORING
20200315787 ยท 2020-10-08
Inventors
- Avraham Zakai (Tel Aviv-Yafo, IL)
- David Mishaly (Shoham, IL)
- Dan Rottenberg (Haifa, IL)
- David Alon (Zichron Yaacov, IL)
Cpc classification
A61F2/2412
HUMAN NECESSITIES
A61F2/246
HUMAN NECESSITIES
A61F2210/0014
HUMAN NECESSITIES
A61B17/12013
HUMAN NECESSITIES
International classification
A61F2/24
HUMAN NECESSITIES
Abstract
A method of treating a native mitral valve without open-heart surgery is disclosed. An expandable prosthesis includes an anchoring portion and an occluding member coupled to the anchoring portion. The prosthesis is loaded into a distal end portion of a delivery catheter and is advanced through a femoral vein and through a pre-made puncture in an atrial septum. The anchoring portion self-expands within the left atrium for anchoring the occluding member in a fixed position. The anchoring portion is preferably a laser cut structure that conforms to the left atrium and uniformly distributes anchoring forces within the left atrium. After deployment, the occluding member prevents blood from flowing from the left ventricle to the left atrium during systole. The occluding member is preferably made from a flexible material, such as pericardial tissue.
Claims
1. A method of treating a native mitral valve without open-heart surgery, the method comprising: loading a mitral valve prosthesis within a delivery catheter, the prosthesis including an anchoring cage and an occluding member for preventing blood flow in one direction; advancing the delivery catheter through a femoral vein and into a right atrium; passing the delivery catheter through a pre-made puncture in an atrial septum and into the left atrium; positioning the anchoring cage within the left atrium; and allowing the anchoring cage to self-expand into contact with a wall of the left atrium, wherein the anchoring cage has a substantially spherical shape for conforming to a geometry of the left atrium and for uniformly distributing anchoring forces along the wall of the left atrium; wherein the anchoring cage maintains the occluding member in a fixed position relative to the native mitral valve and wherein the occluding member prevents blood from flowing from the left ventricle to the left atrium during systole.
2. The method of claim 1, wherein the occluding member comprises at least two pieces of flexible material stitched together, each piece of material having a rounded arch-shaped top portion and a straight bottom portion.
3. The method of claim 2, wherein the flexible material is pericardial tissue.
4. The method of claim 1, wherein the mitral valve prosthesis further comprises support arms for connecting the anchoring cage to the occluding member.
5. The method of claim 1, wherein the anchoring cage is formed by laser cutting a metal tube.
6. The method of claim 5, wherein the metal tube is made of a shape memory material.
7. The method of claim 1, wherein the leaflets of the native mitral valve are capable of opening and closing after the mitral valve prosthesis has been deployed.
8. The method of claim 1, wherein the occluding member is secured to a bottom portion of the anchoring cage.
9. The method of claim 1, wherein the occluding member includes bovine tissue, polyurethane, fabric, biological material, or artificial material.
10. A method of treating a native mitral valve without open-heart surgery, the method comprising: loading a prosthesis within a delivery catheter, the prosthesis including an expandable anchoring member and an occluding member, the anchoring member comprising an anchoring cage shaped to conform to the left atrium; advancing the delivery catheter through a femoral vein and into a right atrium; passing the delivery catheter through a pre-made puncture in an atrial septum and into a left atrium; ejecting the prosthesis from a distal portion of the delivery catheter; and deploying the anchoring cage within the left atrium, wherein the anchoring cage is sized to uniformly distribute anchoring forces along a wall of the left atrium; wherein anchoring cage maintains the occluding member in a substantially fixed position within the heart.
11. The method of claim 10, wherein the occluding member comprises at least two pieces of flexible material stitched together, each piece of material having a rounded arch-shaped top portion and a straight bottom portion, the occluding member configured to block blood flow from the left ventricle to the left atrium during systole and for permitting blood to flow from the left atrium to the left ventricle during diastole.
12. The method of claim 10, wherein the anchoring cage is formed by laser cutting a metal tube.
13. The method of claim 12, wherein the metal tube is made of a shape memory material.
14. The method of claim 10, wherein the leaflets of the native mitral valve are capable of opening and closing after deployment of the anchoring cage within the left atrium.
15. The method of claim 10, wherein the occluding member has a width that is substantially smaller than a length.
16. The method of claim 10, wherein the occluding member includes pericardial tissue, bovine tissue, polyurethane, fabric, biological material, or artificial material.
17. A method of treating a native mitral valve without open-heart surgery, the method comprising: providing a prosthesis comprising an anchoring member and an occluding member attached to the anchoring member, the occluding member comprising at least two pieces of pericardial tissue stitched together, each piece of pericardial tissue having a rounded arch-shaped top portion and a straight bottom portion; compressing the prosthesis; loading the prosthesis into a distal end portion of an elongate delivery catheter; advancing the delivery catheter through a femoral vein and into a right atrium; passing the delivery catheter through an opening in an atrial septum and into the left atrium; and allowing the anchoring member to self-expand into contact with a wall of the left atrium, wherein the anchoring member has an expanded shape that conforms to a shape of the left atrium; wherein the occluding member prevents blood from flowing from the left ventricle to the left atrium during systole and permits blood to flow from the left atrium to the left ventricle during diastole.
18. The method of claim 17, wherein the anchoring member uniformly distributes forces within the left atrium.
19. The method of claim 17, wherein the anchoring member is made of a shape memory material.
20. The method of claim 19, wherein the anchoring member is laser cut from a single tube of Nitinol.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION OF THE INVENTION
[0088] The present invention seeks to reduce the amount of blood that flows into the left atrium from the left ventricle during the systole phase of heart contraction. Most instances of this mitral valve regurgitation are caused by poor coaptation of the mitral valve leaflets that create openings between these leaflets when the mitral valve is closed. The present invention decreases the size of these opening between the mitral valve leaflets, and in some cases completely eliminates the openings, allowing the mitral valve to function with little or no regurgitation. This is achieved in at least some of the example embodiments described in this specification by positioning a member between the two mitral valve leaflets to close or fill up the openings between the leaflets when closed.
FIGS. 1A-4
[0089] One such design can be seen in
[0090] The pocket 106 is preferably created by gluing, stitching, or otherwise adhering at least two layers of the flexible material 104 at or around line 108. These layers can be achieved with two distinct pieces of material, or a single piece of material folded against itself. Preferably, the flexible material 104 is made from pericardial tissue or other biological or artificial materials with similar flexibilities, such as bovine tissue, polyurethane, or as described in U.S. Pat. No. 6,764,510, the contents of which are herein incorporated by reference. The shape of the pocket 106 and the flexibility of the flexible fabric 108 allow the pocket 106 to achieve a deflated position, as best seen in
[0091] While the pocket 106 can be shaped in a variety of different configurations, pocket shapes that facilitate entry and escape of blood from the pocket 106, such as the rounded arch-shape of pocket 106, are preferred. Configurations of the pocket 106 that include sharp corners or rough seams are less preferred due to their disruptive effect on blood flow into and out of the pocket 106. Preferably, the pocket 106 also includes an overall length similar to that of the mitral valve 120 and more preferably substantially the length of the mitral valve commissure, allowing the pocket 106 to fill any openings that may be present along the length of leaflets 122, as seen best in
[0092] The ring 102 is preferably made from an elastic, shape-memory material such as Nitinol which allows the prosthesis 100 to be compressed or loaded into a delivery catheter 110, as seen in
[0093] Once positioned within the heart 124, the prosthesis 100 functions in a similar manner to a heart valve, opening during diastole and closing during systole. More specifically, as blood enters the left atrium from the pulmonary veins 125 near the top of the left atrium 126, the blood flow moves downward towards the mitral valve 120. As the blood flow reaches the mitral valve 120, it pushes against the mitral valve leaflets 122 as the mitral valve 120 is opened by the papillary muscles. The blood flow also pushes against the pocket 106 of the prosthesis 100, forcing out any blood that may be within the pocket 106 and causing the pocket 106 to assume a substantially deflated or compressed position, as seen in
[0094] During systole, backpressure from the blood in the left ventricle 128 presses against the mitral valve leaflets 122, as the papillary muscles move these leaflets 122 to a closed position. Additionally, this backpressure of blood in the left ventricle 128 enters the pocket 106 of the prosthesis 100, causing the pocket 106 to achieve an expanded shape, as seen in
[0095] Due in part to the dynamic, flexible nature of the pocket 106, the prosthesis 100 can expand to fill a wide range of opening sizes between the leaflets 122 without the need for an equally wide range of pocket sizes. In other words, the same size pocket 106 can expand to fill a relatively small opening or a relatively large opening between the mitral valve leaflets 122. Thus, the same size prosthesis 100 may be appropriate for a patient with relatively severe mitral valve regurgitation as well as relatively mild mitral valve regurgitation. Different sizes of prosthesis 100 may be appropriate, however, for different size mitral valves 120, since it is preferred that the pocket 106 extends along the length of the commissure of the mitral valve or the length of the meeting line between the two leaflets.
[0096] The prosthesis 100 is preferably delivered to the left atrium 126 percutaneously by a catheter 110, as seen in
[0097] Alternately, the prosthesis 100 can be inserted into the left atrium 126 through an opening in the atrial wall of the heart 125 during open-heart surgery. Although the prosthesis 100 can be seen and positioned more easily during open-heart procedures, percutaneous delivery is less invasive and therefore includes a substantially lower risk of complications.
FIGS. 5A-8B
[0098] Another preferred embodiment of a prosthesis 200 according to the present invention can be seen in
[0099] The pocket 206 is supported by support arms 204 and bottom support 208 which provide a support framework for the pocket 206. Preferably the side arms 204 and the bottom support 208 are a single, unitary wire that connect to the anchoring loops 202, however multiple segments of wire can be connected together, for example by welding or soldering, as well. As with the previously described embodiment of the prosthesis 100, the support arms 204 and the bottom support 208 are preferably composed of an elastic, memory-shape material, such as Nitinol, which allows the prosthesis 200 to be compressed and loaded into a catheter 110, as seen in
[0100] The pocket 206 is similar to the pocket 106 of the previous embodiment, preferably being composed of a flexible biological or artificial material that is sized and shaped to form a pocket-shape with an opening directed opposite to the anchoring loops 202. The pocket 206 can be directly stitched, glued, or adhered to the outer support arms 204 for support. Alternately, the flexible fabric of the pocket 206 can be stitched to form an elongated passage for the support arms 204 on the outer surface of the pocket 206.
[0101] As best seen in
[0102] The prosthesis 200 is preferably delivered to the left atrium 126 by a percutaneous delivery catheter 110 but can also be implanted during open-heart surgery, as described in regards to the prosthesis 100. Since the pocket 206 has a horizontally elongated shape that requires a specific orientation within the mitral valve 120, percutaneous delivery of the prosthesis 200 to the proper position may be more difficult than delivery during open-heart surgery. Accordingly, the delivery catheter 110 may include a retrieval thread 210 and a push rod 212 as seen in
[0103] Preferably, the retrieval thread 210 is composed of a thin but strong material such as metal, silk, or polypropylene, and is a single segment. Both free ends of the retrieval thread 210 are positioned at a proximal end of the delivery catheter 110, while the body of the thread 210 extends through the deliver catheter 110, through each anchoring loop 202 and back through the catheter 110.
[0104] Depending on the configuration of the prosthesis 200 in an expanded state, the retrieval thread 210 alone may not provide the necessary force to fully recompress and recapture the prosthesis 200. In such situations, the pusher rod 212 may be used in conjunction with the retrieval thread 210 to manipulate the prosthesis 200 into a shape acceptable for recapture within the delivery catheter 110. For example, the operator of the delivery catheter 110 may pull on the retrieval thread 210 while pushing on the anchoring loops 202 with the pusher rod 212. The simultaneous pushing and pulling deform the anchoring loops 202 into an elongated shape that can more easily be recaptured by the delivery catheter 110, allow the user to reposition the distal end of the delivery catheter 110 and redeploy the prosthesis 200.
FIGS. 9A-9E
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FIGS. 10A-11
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[0107] Unlike the embodiments previously described in this specification, the prosthesis 300 includes an anchoring cage 302 that is unitary with the support arms 304. Preferably, both the anchoring cage 302 and the support arms 304 are cut from a single metal tube, such as by laser cutting the desired pattern into the tube or by other techniques used to manufacture stents. The metal of the tube is preferably composed a shape memory material, such as those commonly used for stents such as Nitinol. In this regard, the anchoring cage 302 can more generally be described as an anchoring framework or an anchoring structure.
[0108] Once expanded within the left atrium 126, the anchoring cage 302 contacts the tissue of the left atrium 126 in more positions that embodiments previously described in this specification and therefore more uniformly distributes the anchoring force within the left atrium 126. Additionally, the expanded shape of the anchoring cage 302 can be shaped to better conform to the geometry of the left atrium 126 and therefore more precisely position the pocket 306 at a desired location.
[0109] As with the previously described embodiments of this specification, the prosthesis 300 is preferably delivered percutaneously with a delivery catheter 110 as seen in
FIGS. 12A-13
[0110]
[0111] In contrast to the previously described embodiments, the prosthesis 400 includes multiple anchoring loops 402 that form a spherical, lemon shape having a terminating region 408. The overall shape of the anchoring loops 402 expand to apply pressure against the left atrium 126 at different angles which better maintains the position of the prosthesis 400. Additionally, the terminating region 408 can press against the tissue of the left atrium 126 or can alternatively be positioned within an incision within the wall of the left atrium 126 (e.g. a percutaneous access incision within the atrium septum) to provide further anchoring support.
[0112] The body of the prosthesis 400 includes wires 402A-402E that are shaped to form the anchoring loops 402, as well as two pocket supports 404. Wires 402B, 402C, and 402D are shaped to have a generally circular shape with each of the free ends captured by terminating region 408. In this respect, each wire 402B, 402C, and 402D forms a single loop of the prosthesis 400.
[0113] One end of wire 402A is fixed within terminating region 408 while the other end extends down to form a pocket support 404, including an arch-shape in between the two ends having a similar shape to those formed by wires 402B, 402C, and 402D. The second pocket support 404 is formed from wire 404E which is similarly fixed within terminating region 408. As with the previously described embodiments described in this specification, the pocket 406 is fixed to the pocket supports 404, thereby maintaining the pocket 406 at a desired location within the mitral valve 120, as best seen in
FIGS. 14A-16B
[0114] In another preferred embodiment illustrated in
[0115] As seen in
FIGS. 17A-17D
[0116]
[0117] In contrast, present prosthesis 600 includes anchoring wires 602 shaped to have an asymmetrical egg structure that more closely resembles the asymmetrical interior of the left atrium 126. Since the asymmetry of the anchoring wires 602 matches the natural asymmetry of the left atrium 126, the prosthesis 600 expands and orients itself in a predetermined position, providing stable anchoring and consistent alignment of the pocket 606 with the mitral valve 120. Further, this asymmetrical design facilitates delivery and deployment from the position of an incision through the atrial septum, since the prosthesis 600 expands to firmly engage the geometry of the left atrium 126. In this regard, the anchoring wires 602 can more generally be described as an anchoring framework or an anchoring structure.
[0118] The pocket 606 also includes a radial or cylinder shape when fully expanded, and can more generally be described as an expandable occluding member or a coaptation member. The radial shape imparts a uniform hydraulic function that is similar, regardless of the rotationally orientation of the pocket 606 relative to the mitral valve leaflets 122 (i.e. the commissure of the mitral valve 120). In this respect, the prosthesis 600 can be deployed to a greater number of orientations without adversely affecting the reduction of regurgitation.
FIGS. 18A-18D
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[0120] As best seen in
FIGS. 19A-19D
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[0122] In contrast to the previously described prosthesis 700, the prosthesis 800 includes a pocket support wire 804 that not only supports the structure of the pocket 806, as described in other embodiments in this specification, but also wraps around a cylinder 808, then branches radially outward into loop shapes 804A, as best seen in
[0123] The looped regions 804A of the pocket support wire 804 assist the freely rotating pocket 806 in orienting itself to a desired position within the mitral valve 120. Additionally, these outer looped regions 804A can be sized and shaped to provide support to the pocket 806 by resting on the annulus of the mitral valve 120.
[0124] Alternately, the looped regions of the pocket support wire 804 can be shaped to at least partially interlock with a portion of the anchoring wires 802 to allow the anchoring wires 802 to freely rotate within a range, determined and therefore restricted by the length of the loops of the pocket support wire 804. Such a rotational restriction may better assist the surgeon in delivering and deploying by allowing at least some degree of rotational control over the pocket 806 in a deployed configuration.
FIGS. 20A-21B
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[0126] However, the prosthesis 900 includes two separately deployable support structures: the previously mentioned anchoring wires 902 and inner support wires 904. The inner support wires 904 include elongated region 904A and anchoring region 904B which continues within the pocket 906 as support wires 908. The anchoring wires 902 and inner support wires 904 can more generally be described as an anchoring framework or an anchoring structure.
[0127] As best seen in
[0128] The expanded shape of the anchoring region 904B is preferably sized and shaped to engage at least a portion of the annulus of the mitral valve 120. In this respect, the user can direct the pocket 906 to a desired position within the mitral valve 120 while the anchoring region 904B expands to at least partially anchor the pocket 906 in place. Once the user has achieved a desired position for the pocket 906, the remaining anchoring wires 902 can be deployed from the delivery catheter 110, allowing them to expand to press against the left ventricle 126, thereby further anchoring the prosthesis 900 in place.
FIGS. 22A-22C
[0129]
[0130] In addition to these similarities, the prosthesis 1000 includes region 1002A of anchoring wires 1002 that curve towards the open end of the pocket 1006. When expanded within the left atrium 126, the region 1002A of the present invention at least partially contacts the annulus of the mitral valve 120. This annulus support prevents the pocket 1006 from being pushed past the mitral valve 120 into the left ventricle 128, maintaining the overall vertical position of the prosthesis within the left atrium 120. In this respect, the anchoring wires 1002 can more generally be described as an anchoring framework or an anchoring structure.
FIGS. 23A-23D
[0131] Turning now to
[0132] However, the free ends of the anchoring wires 1102 are wound around lower loops 1104, allowing the loops of anchoring wire 1102 to pivot on the lower loops 1104 to achieve more complex anchoring configurations. By achieve more complex anchoring configurations, the prosthesis 1100 can provide better support and therefore more constant positioning of the pocket 1106 over time. In this regard, the anchoring wires 1102 can more generally be described as an anchoring framework or an anchoring structure.
FIGS. 24A-24E
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[0134] To achieve additional complexity with the design of the anchoring wire 1202, portions of the anchoring wire fixed to each other with knitting 1208, as best seen in
FIG. 25
[0135] Turning to
[0136] The stent anchor 1302 can be composed of a variety of different materials and structures as is known in the art. For example, some stent techniques can be seen in U.S. Pat. Nos. 6,936,067; 6,929,658; 6,926,743; 6,923,828; and 6,902,575; the contents of each are herein incorporated by reference.
FIGS. 26A-26B
[0137] Turning to
[0138] In this respect, the prosthesis 1400 can be delivered via an incision in the atrial septum 125, first positioning the pocket 1406 within the mitral valve 120, then extending the septum attachment arms 1404 against both the left and right sides of the atrial septum 125 for anchoring support. The positioning arm 1402 substantially occludes the incision within the atrial septum 125, while the septum attachment arms 1402 retain the septal tissue around the positioning arm 1402, preventing blood from passing between through the septum 125.
[0139] While the preferred embodiments disclosed in this specification include expandable pockets, it should be understood that other designs can be used with the anchoring designs contemplated by the present invention. For example, a solid and preferably flexible plate member can alternatively be used, having a similar shape and size as described in regards to the pockets of the embodiments of this specification.
[0140] Preferably, the solid member is relatively soft, having a flexibility that allows some compression, especially when contacted by mitral valve leaflets. More preferably, the solid member could be created by adhering two pieces of pericardial tissue together and providing supporting members or wires similar to those described in regards to the pocket in the previous embodiments. In place of supporting members, Nitinol string may be attached to both the solid member and the left ventricle 128, preventing the solid member from moving into the left atrium 126. Alternatively, the solid member can be composed of a resilient, biocompatible polymer material such as polyurethane.
[0141] Preferably, the embodiments of this specification may also include flexible polymeric sheets, such as polyurethane, that connect the anchoring loops or anchoring wire that contact the left atrium 126. In this respect, the flexible sheets further decreases stress on the left atrium walls by more evenly distributing anchoring force.
[0142] It should be understood different elements of the embodiments of this application can be combine to form additional design contemplated by the present invention. For example, the septal anchoring prosthesis 1400 shown in
[0143] While the embodiments disclosed in the present invention have been specifically described as used with the mitral valve of the heart, it is also contemplated that these embodiments may be adapted for use with other heart valves. For example, the anchoring structures can be modified to press against a different geometry within the heart and the pocket can be adapted to a different shaped valve, such as a tricuspid valve.
[0144] Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed invention. Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof.