Patent Application
20170056176
This disclosure pertains generally to prosthetic devices and related methods for preventing or reducing regurgitation through native heart valves, as well as devices and related methods for implanting such prosthetic devices.
The native heart valves (i.e., the aortic, pulmonary, tricuspid, and mitral valves) serve critical functions in assuring the forward flow of an adequate supply of blood through the cardiovascular system. These heart valves can be rendered less effective by congenital malformations, inflammatory processes, infectious conditions, or disease. Such damage to the valves can result in serious cardiovascular compromise or death. For many years the definitive treatment for such disorders was the surgical repair or replacement of the valve during open-heart surgery. However, such surgeries are highly invasive and are prone to many complications. Therefore, elderly and frail patients with defective heart valves often went untreated. More recently, transvascular techniques have been developed for introducing and implanting prosthetic devices in a manner that is much less invasive than open-heart surgery. Such transvascular techniques have increased in popularity due to their high success rates.
A healthy heart has a generally conical shape that tapers to a lower apex. The heart is four-chambered and comprises the left atrium, right atrium, left ventricle, and right ventricle. The left and right sides of the heart are separated by a wall generally referred to as the septum. The native mitral valve of the human heart connects the left atrium to the left ventricle. The mitral valve has a very different anatomy than other native heart valves. The mitral valve includes an annulus portion, which is an annular portion of the native valve tissue surrounding the mitral valve orifice, and a pair of cusps, or leaflets extending downward from the annulus into the left ventricle. The mitral valve annulus can form a D-shaped, oval, or otherwise out-of-round cross-sectional shape having major and minor axes. The anterior leaflet can be larger than the posterior leaflet, forming a generally C-shaped boundary between the abutting free edges of the leaflets when they are closed together.
When operating properly, the anterior leaflet and the posterior leaflet function together as a one-way valve to allow blood to flow only from the left atrium to the left ventricle. The left atrium receives oxygenated blood from the pulmonary veins. When the muscles of the left atrium contract and the left ventricle dilates, the oxygenated blood that is collected in the left atrium flows into the left ventricle. When the muscles of the left atrium relax and the muscles of the left ventricle contract, the increased blood pressure in the left ventricle urges the two leaflets of the mitral valve together, thereby closing the one-way mitral valve so that blood cannot flow back into the left atrium and is, instead, expelled out of the left ventricle through the aortic valve. To prevent the two leaflets from prolapse under pressure and folding back through the mitral valve annulus towards the left atrium, a plurality of fibrous cords called chordae tendineae tether the leaflets to papillary muscles in the left ventricle.
Mitral regurgitation occurs when the native mitral valve fails to close properly and blood flows into the left atrium from the left ventricle during the systole phase of the cardiac cycle. Mitral regurgitation is the most common form of valvular heart disease. Mitral regurgitation has different causes, such as leaflet prolapse, dysfunctional papillary muscles, and/or stretching of the mitral valve annulus resulting from dilation of the left ventricle. Mitral regurgitation at a central portion of the leaflets can be referred to as central jet mitral regurgitation, and mitral regurgitation nearer to one commissure (i.e., location where the leaflets meet) of the leaflets can be referred to as eccentric jet mitral regurgitation.
Some prior techniques for treating mitral regurgitation include stitching edge portions of the native mitral valve leaflets directly to one another (known as an Alfieri stitch). Other prior techniques include the implantation of a fixation member that mimics an Alfieri stitch by fixing edge portions of the native leaflets to one another. One commercially available fixation device is the Mitraclip®, available from Evalve, Inc. A substantial number of patients treated with an Alfieri stitch or a fixation member have experienced poor clinical outcome, that is, significant residual mitral regurgitation. In some cases, residual mitral regurgitation can be treated by implanting one or more additional fixation members or additional stitches. However, additional fixation members or stitches can increase the pressure gradient across the mitral to an unacceptable level. Thus, there exists a need for treating patients that experience mitral regurgitation after implantation of a fixation device or treatment with an Alfieri stitch.
The present disclosure concerns embodiments of an implantable device that are used to treat an insufficient heart valve that has been previously treated by implantation of a fixation device or an Alfieri stitch that is secured to opposing portions of the native leaflets. Such fixation devices or Alfieri stitches typically are implanted in the native mitral valve. Thus, embodiments disclosed herein are described in the context of treating a native mitral valve. However, it should be understood that any of the disclosed embodiments can be used to treat the other valves of the heart (the aortic, pulmonary, and tricuspid valves).
In one representative embodiment, an implantable device for remodeling a native mitral valve having two native leaflets and a fixation device or an Alfieri stitch secured to respective free edges of the leaflets is configured to be coupled to the fixation device or Alfieri stitch and apply a remodeling force to the native mitral valve that draws the native leaflets toward each other to promote coaptation of the leaflets.
In some embodiments, the remodeling force applied by the implantable device draws the leaflets and the chordae tendineae closer toward the left atrium. In certain embodiments, the implantable device comprises a tension member configured to be coupled to the fixation device or Alfieri stitch and an anchor member connected to the tension member. The tension member can comprise, for example, an elongated, flexible piece of material, such as a suture, string, cord, wire, or similar material. The anchor member can be configured to engage tissue in or adjacent the heart, such as tissue in the left atrium, the intra-atrial septum, and/or a pulmonary vein. In some embodiments, the anchor member can comprise an expandable stent sized to be implanted within a pulmonary vein, which can include an eyelet through which the tension member can extend. In other embodiments, the anchor member can comprise a first anchor portion and a second anchor portion, the first anchor portion being configured to engage the intra-atrial septum in the left atrium and the second anchor portion being configured to engage the intra-atrial septum in the right atrium.
In some embodiments, the remodeling force applied by the implantable device causes the leaflets to be twisted about an axis extending parallel to the flow of blood from the left atrium to the left ventricle. In certain embodiments, the implantable device can be configured to be anchored to tissue in the left ventricle or the left atrium.
In another representative embodiment, a method for treating a native mitral valve of a heart having two native leaflets and a fixation device or an Alfieri stitch secured to respective free edges of the leaflets comprises delivering a remodeling device into the heart, coupling the remodeling device to the fixation device or Alfieri stitch, and applying a remodeling force to the native mitral valve via the remodeling device, the remodeling force drawing the leaflets toward each other to promote coaptation of the leaflets.
In certain embodiments, the method further comprises anchoring an anchor member of the remodeling device to tissue in or adjacent the heart to maintain the remodeling force on the native mitral valve.
In certain embodiments, the remodeling device comprises a tension member that is coupled to the fixation device or Alfieri stitch and is held in tension by an anchor member of the remodeling device that is anchored to tissue in or adjacent the left atrium. In some embodiments, the tension member forms a loop around the fixation device or Alfieri stitch and has two ends connected to the anchor member.
In another representative embodiment, a method for treating a native mitral valve of a heart having two native leaflets and a fixation device or an Alfieri stitch secured to respective free edges of the leaflets comprises coupling a docking member to the fixation device or Alfieri stitch and deploying a prosthetic valve within the docking member. In some embodiments, the act of coupling a docking member to the fixation device or Alfieri stitch comprises deploying a rail around the fixation device or Alfieri stitch and advancing the docking member along the rail to a location adjacent the native mitral valve within the left atrium. In some embodiments, the docking member comprises a radially extending flange that forms a seal against the inner surface of the left atrium. In some embodiments, the prosthetic valve is delivered into the heart in a radially compressed state by a delivery catheter and then radially expanded to an expanded state within the docking member.
In another representative embodiment, a method for treating a native mitral valve of a heart having two native leaflets and a fixation device or an Alfieri stitch secured to the leaflets at a location between the commissures so as to define two orifices between the leaflets separated by the fixation device or Alfieri stitch comprises implanting a prosthetic valve within one of the orifices. In some embodiments, the method further comprises implanting another prosthetic valve in the other orifice. In some embodiments, the prosthetic valves are connected to each other by a connecting member.
In another representative embodiment, an assembly for treating a native mitral valve of a heart having two native leaflets and a fixation device or an Alfieri stitch secured to respective free edges of the leaflets comprises a docking member configured to be coupled to the fixation device or Alfieri stitch and a prosthetic valve configured to be deployed within the docking member.
The foregoing and other objects, features, and advantages of the invention will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.
For purposes of this description, certain aspects, advantages, and novel features of the embodiments of this disclosure are described herein. The disclosed methods, apparatuses, and systems should not be construed as limiting in any way. Instead, the present disclosure is directed toward all novel and nonobvious features and aspects of the various disclosed embodiments, alone and in various combinations and sub-combinations with one another. The methods, apparatuses, and systems are not limited to any specific aspect or feature or combination thereof, nor do the disclosed embodiments require that any one or more specific advantages be present or problems be solved.
Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.
Although the operations of some of the disclosed methods are described in a particular, sequential order for convenient presentation, it should be understood that this manner of description encompasses rearrangement, unless a particular ordering is required by specific language. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed methods can be used in conjunction with other methods. As used herein, the terms “a”, “an”, and “at least one” encompass one or more of the specified element. That is, if two of a particular element are present, one of these elements is also present and thus “an” element is present. The terms “a plurality” of and “plural” mean two or more of the specified element.
As used herein, the term “and/or” used between the last two of a list of elements means any one or more of the listed elements. For example, the phrase “A, B, and/or C” means “A”, “B,”, “C”, “A and B”, “A and C”, “B and C”, or “A, B, and C.”
As used herein, the term “coupled” generally means physically coupled or linked and does not exclude the presence of intermediate elements between the coupled items absent specific contrary language.
In another embodiment, the tension member 24 need not form a loop around the fixation device 10 and instead can have a first, lower end secured to the fixation device and an upper end secured to an anchor member deployed in or adjacent the heart, such as in the left atrium, the atrial septum, and/or a pulmonary vein.
The deployment catheter 44 can be advanced through a lumen of the trans-septal catheter 42 until a distal end portion 46 of the deployment catheter 44 extends outwardly from the distal end of the trans-septal catheter 42. The distal end portion 46 of the deployment catheter 44 desirably is configured to form a 180-degree curve or bend so that it can be placed to extend through orifices 26, 28 and around the fixation device 10, as shown in
After the curved distal end portion 46 is placed around the fixation device 10, a tension member 24 can be advanced through and deployed from the distal end of the deployment catheter 44. The snare 48 can then be advanced from the trans-septal catheter 42 to capture and retract the tension member 24. A snare loop 50 of the snare 48 is placed around the distal end of the tension member and retracted back into the trans-septal catheter 42. The snare 48 can be retracted out of the proximal end of the trans-septal catheter 42 so that the opposing ends of the tension member 24 reside outside the body.
As shown in
Referring to the
Alternatively, a fastener 58 (such as a suture clip) can be advanced over the tension member 24 and pushed against the second anchor portion 56 before severing the tension member 24. The fastener 58 can be a suture clip, or another type of fastener that can be deployed from a catheter and secured to a suture within the patient's body. Various suture clips and deployment techniques for suture clips that can be used in the methods disclosed in the present application are disclosed in U.S. Publication Nos. 2014/0031864 and 2008/0281356 and U.S. Pat. No. 7,628,797, which are incorporated herein by reference. In the case of a slidable fastener, the fastener 58 can be movable along the tension member 24 in a direction toward the septum, and configured to resist movement along the tension member in the opposite direction.
In particular embodiments, the deployment catheter 44, the snare 48, and the tension member 24 can be pre-loaded within the trans-septal catheter 42 and all components can be delivered into the left atrium together as a unit. Each component can then be advanced from the trans-septal catheter 42 in the sequence described above.
The stent 60 can be a self-expandable stent (made of a self-expandable material, such as Nitinol) or a plastically-expandable stent (made of a plastically expandable material, such as stainless steel or a cobalt-chromium alloy). In the case of a self-expandable stent, the stent can be delivered to the heart in a radially compressed state inside a sheath of a delivery catheter, as known in the art. The stent can be deployed from the sheath into the pulmonary vein, whereupon the stent can self-expand to a radially expanded state against the inner surface of the pulmonary vein. In the case of a plastically-expandable stent, the stent can be radially compressed on a balloon (or equivalent expansion mechanism) of a delivery catheter and advanced through the patient's vasculature into the pulmonary vein, whereupon the balloon can be inflated to expand the stent against the inner surface of the pulmonary vein.
After deploying the tension member 24 and the stent 60, the tension member 24 can be pulled proximally to apply a remodeling force 16 to remodel the heart tissue. A fastener 58 can then be advanced over the tension member 24 against the eyelet 64 to maintain tension on the tension member, after which the tension member can be severed proximal to the fastener. In particular embodiments, the stent 60 and the fastener 58 can be pre-loaded on the tension member 24 within the deployment catheter 44 (not shown in
Referring now to
Respective fasteners (not shown in
Referring now to
In use, the remodeling device 202 can be delivered to the left atrium using a delivery catheter (not shown) and secured to the fixation device 10. While the remodeling device 202 is still connected to the delivery catheter, the delivery catheter can be rotated in the direction of arrow 200, which in turn rotates the remodeling device 202 and draws the native leaflets 12, 14 closer toward each as shown in
Each prosthetic valve 230a, 230b can comprise a radially compressible and expandable annular stent or frame 234 and one or more leaflets 236 supported in the frame to regulate the flow of blood through the valve in one direction. The prosthetic valves can be self-expandable or plastically-expandable. Some examples of prosthetic valves that can be used are disclosed in, for example, U.S. Pat. Nos. 7,993,394; 7,393,360; and 8,652,202, and U.S. Publication No. 2012/0123529, which are incorporated herein by reference.
In some embodiments, it may be desirable to implant a prosthetic valve in only one of the orifices 26, 28 while leaving the other orifice 26, 28 without a prosthetic valve.
Any of the embodiments described herein can be used with a previously implanted fixation device 10, or a newly implanted fixation device 10. For example, any of the embodiments described herein can be implanted in a heart in which a fixation device 10 had been implanted years, months, weeks, or days earlier.
In other cases, any of the embodiments described herein can be implanted in a heart immediately following the implantation of a fixation device 10. Thus, any of the methods for treating an insufficient heart valve disclosed herein can include the step of implanting a fixation device 10 in the native heart valve.
In view of the many possible embodiments to which the principles of the disclosed invention may be applied, it should be recognized that the illustrated embodiments are only preferred examples of the invention and should not be taken as limiting the scope of the invention. Rather, the scope of the invention is defined by the following claims. We therefore claim as our invention all that comes within the scope and spirit of these claims.
This application claims the benefit of U.S. Provisional Patent Application No. 62/209,796, filed Aug. 25, 2015, which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62209796 | Aug 2015 | US |
