MODULAR TRANSCATHETER HEART VALVE AND IMPLANTATION METHOD
Disclosed herein are valves, such as an aortic valve replacement can be delivered via a transcatheter approach can be deployed by a single operator through a lower profile (e.g., 8-12 French, or even less) delivery system. Lower profile delivery systems can advantageously potentially expedite procedures and reduce complications, as they tend to be easier to navigate through the vascular anatomy. In some embodiments, the valve system can be deployed in a multiple stage approach as two separate components, rather than a single unified component; first a stent, followed by a discrete structure such as a valve support that includes the valve leaflets. The components can be positioned separately during delivery at different locations in and over the catheter. The stent can include a pair of rows of hooks directed in directions opposite to one another. The valve support can include struts having retaining structures that form a spherical configuration when retained together by a grasping member to keep the valve folded and conical during delivery thereof inside the catheter.
This application claims the benefit under 35 U.S.C. §120 as a continuation application of U.S. patent application Ser. No. 14/563,933 filed on Dec. 8, 2014, which in turn claims the benefit under 35 U.S.C. §119(e) as a nonprovisional of U.S. Pat. App. No. 61/938,620 filed on Feb. 11, 2014. Both of the foregoing priority applications are hereby incorporated by reference in their entireties.
BACKGROUNDThe invention relates to, in some aspects, heart valves and methods of using the same.
SUMMARYIn some embodiments, disclosed herein is a heart valve replacement system. The system can include a delivery catheter having a proximal end, a central lumen, and a distal end. The system can also include a scaffold stent configured to fit over a portion of the delivery catheter proximate the distal end of the delivery catheter. The scaffold stent can have a reduced delivery configuration and an expanded configuration. The system can also include a valve support comprising a frame and a plurality of leaflets attached to the frame. The frame can include a plurality of struts, such as 2, 3, or more struts extending axially from the frame. Each strut can have a retaining structure at its downstream end. The valve support can have a reduced delivery configuration where the valve support can be housed within the central lumen of the delivery catheter. The valve support can be configured to be delivered independent of the scaffold stent. The system can also include a grasping member, such as a bioptome or snare for example, configured to operably attach to the retaining structures of the struts to compress the valve leaflets. The system can also include an expandable member, e.g., a balloon, proximate the distal end of the delivery catheter, the expandable member configured to expand the scaffold stent. The scaffold stent can also be self-expandable, and a retractable sheath or other retaining mechanism can be configured to maintain the scaffold stent in a reduced configuration during delivery. The retaining structures of the struts can be releasably attached to the grasping member, and the retaining structures can couple together to form a sphere-like shape. The delivery catheter can have a size of less than or equal to 12 French, such as between 8 French and 12 French. The frame of the valve support can be made of a shape memory mesh material. The valve skirt can be attached to an inner or outer surface of the scaffold stent, and can be made of, for example, a fabric material. The frame of the valve support can include a generally cylindrical portion, and a flap portion on an upstream end of the frame configured to rest against an upstream end of the scaffold stent. The flap portion can be configured to minimize or prevent paravalvular regurgitation. The system can be configured to replace a native aortic, mitral, tricuspid, or pulmonic valve.
Also disclosed herein is a transluminal method of delivering a heart valve replacement, such as an aortic valve replacement. The method can include one or more of the steps of providing a delivery catheter carrying a scaffold stent over a distal portion of the delivery catheter, the scaffold stent having an upstream end and a downstream end, the delivery catheter also comprising a valve support having a frame, a plurality of valve leaflets, and a distal flap portion, the valve support carrying a prosthetic aortic valve releasably connected to a delivery cable, the valve support not connected to the scaffold stent. The method can also include positioning the distal end of the delivery catheter in the left ventricle, to position the scaffold stent at the level of the native aortic valve annulus. The method can further include expanding the scaffold stent within the native aortic valve annulus; partially moving the valve support out of the delivery catheter, thereby expanding the distal flap portion; retracting the valve support such that the distal flap contacts the upstream end of the scaffold stent; disconnecting the valve from the delivery cable; and withdrawing the delivery catheter and the delivery cable. Disconnecting the valve from the delivery cable can include releasing a grasping member, e.g., a bioptome or snare for example, connected to retaining structures on proximal ends of struts extending from the valve support, whereby release of the bioptome causes the valve leaflets to completely unfold. The method can also include securing the valve support to the scaffold stent. Securing the valve support to the scaffold stent can include connecting the frame of the valve support to hooks on a radial inwardly-facing surface of the scaffold stent. Expanding the scaffold stent within the native aortic valve annulus can include balloon-expanding the scaffold stent, or allowing the scaffold stent to self-expand.
FIGS. 5 and 5A-5G illustrate a system and multiple-stage method for delivering a transcatheter heart valve, according to some embodiments of the invention.
Heart valve replacement has become a routine surgical procedure for patients suffering from valve regurgitation or stenotic calcification of the leaflets. While certain procedures may be performed using minimally-invasive or transluminal techniques, the vast majority of valve replacements still entail full sternotomy and placing the patient on cardiopulmonary bypass. Traditional open surgery inflicts significant patient trauma and discomfort, requires extensive recuperation times and may result in life-threatening complications.
More recently, efforts have been focused on percutaneous transluminal delivery of replacement cardiac valves to solve the problems presented by traditional open surgery and minimally-invasive surgical methods. In such methods, a valve prosthesis is compacted for delivery in a catheter and then advanced, for example, through an opening in the femoral artery and through the descending aorta to the heart, where the prosthesis then is deployed over the aortic valve annulus. Although transluminal techniques have attained widespread acceptance with respect to delivery of stents to restore vessel patency, only mixed results have been obtained with respect to percutaneous delivery of relatively more complicated valve prostheses. Stent-supported systems for positioning of a replacement heart valve could potentially have issues with regard to migration from the target valve site, and vascular complications due to the relatively high profile of the valve system. What is needed are replacement valves that are less prone to migration, and furthermore can be delivered safely and efficiently via a low-profile delivery system.
The deployment of a transcatheter valve, such as an aortic or mitral valve for example, as a whole unit can require relatively large-diameter catheters or delivery systems. Disclosed herein are valves, such as an aortic valve replacement that can be delivered via a transcatheter approach and can be deployed by a single operator through a lower profile (e.g., 8-12 French, or even less) delivery system. Lower profile delivery systems can advantageously potentially expedite procedures and reduce complications, as they tend to be easier to navigate through the vascular anatomy. In some embodiments, the valve system can be deployed in a multiple stage approach as two separate components, rather than a single unified component; first a scaffold stent, followed by a discrete structure such as a valve support that includes the valve leaflets. The components can be positioned separately during delivery at different locations in and over the catheter. The stent can include a pair of rows of hooks disposed in a parallel or substantially parallel manner or directed in directions opposite to one another. The valve support can include struts having retaining structures that form a spherical configuration when retained together by a grasping member to keep the valve leaflets folded and conical during delivery thereof inside the catheter, advantageously creating a significantly reduced delivery profile.
The scaffold stent 110 can have an inner surface and an outer surface, the outer surface configured to exert a radially outward force and engage with, for example, the native valve annulus when the scaffold stent 110 is in an expanded configuration. The valve support 109 can engage with the scaffold stent 110 via a radial outward mechanical force, and/or anchors such as hooks for example, as described in greater detail below. In some embodiments, the scaffold stent 110 can have an inner, or an outer diameter of between about 20 mm and about 30 mm, or between about 23 mm and about 29 mm.
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The valve support 109 can also include a valve skirt (not shown) that is operably attached, by sutures, adhesives, or other means, to the inner or outer surface of the valve support. The valve skirt can be made of any appropriate material, such as a metal, a synthetic polymer such as PET, Dacron, ePTFE, or PTFE for example, and/or a biological material such as pericardium, pleura, peritoneum, small intestinal submucosa, collagen, or the like. The valve skirt can assist in reducing paravalvular leak and associated regurgitation around the valve. Operably coupled to the valve support 109, e.g., via the valve skirt are the valve leaflets 105. Each valve could include any number of leaflets, such as 2, 3, or 4 leaflets for example. The leaflets 105 can also be made of any appropriate material including materials described above in connection with the valve skirt. In some embodiments, the lateral ends of the leaflets 105 include enlarged regions that are folded to both form commissural joints and fasten the commissural joints to the valve support 109. The skirt and leaflets 105 can, in some embodiments, be configured so that the joints align with contours of the cell pattern of the valve support 109.
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In other embodiments, the scaffold stent 110 is self-expandable, and made of a shape memory material such as nitinol as described elsewhere herein. The scaffold stent 110 can be mounted over a distal portion of the delivery catheter 300 as described above, which can be 8-12 French or less in some cases. The scaffold stent 110 may have a slightly flared distal end in some embodiments, and in some cases be covered on its inner and/or outer surface by a fabric such as PTFE. The stent 110 can be covered by a restraint feature such as a retractable sheath having sufficient column strength to prevent the stent 110 from transforming from the reduced configuration to the expanded configuration while undeployed. The stent 110 can be resheathable prior to delivery, to permit repositioning if necessary. Once the stent 110 is positioned over the native valve annulus, the sheath can be retracted or otherwise removed, allowing the stent 110 to fully self-expand and be positioned at the level of the native valve annulus.
The delivery catheter 200 can be introduced over a guidewire 140 as shown. As illustrated in
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It is contemplated that various combinations or subcombinations of the specific features and aspects of the embodiments disclosed above may be made and still fall within one or more of the inventions. Further, the disclosure herein of any particular feature, aspect, method, property, characteristic, quality, attribute, element, or the like in connection with an embodiment can be used in all other embodiments set forth herein. Accordingly, it should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the disclosed inventions. Thus, it is intended that the scope of the present inventions herein disclosed should not be limited by the particular disclosed embodiments described above. Moreover, while the invention is susceptible to various modifications, and alternative forms, specific examples thereof have been shown in the drawings and are herein described in detail. It should be understood, however, that the invention is not to be limited to the particular forms or methods disclosed, but to the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the various embodiments described and the appended claims. Any methods disclosed herein need not be performed in the order recited. The methods disclosed herein include certain actions taken by a practitioner; however, they can also include any third-party instruction of those actions, either expressly or by implication. For example, actions such as “positioning the distal end of the delivery catheter in the native aortic valve annulus” include “instructing the positioning of the distal end of the delivery catheter in the native aortic valve annulus.” The ranges disclosed herein also encompass any and all overlap, sub-ranges, and combinations thereof. Language such as “up to,” “at least,” “greater than,” “less than,” “between,” and the like includes the number recited. Numbers preceded by a term such as “approximately”, “about”, and “substantially” as used herein include the recited numbers, and also represent an amount close to the stated amount that still performs a desired function or achieves a desired result. For example, the terms “approximately”, “about”, and “substantially” may refer to an amount that is within less than 10% of, within less than 5% of, within less than 1% of, within less than 0.1% of, and within less than 0.01% of the stated amount.
Claims
1. A heart valve replacement system, comprising:
- a delivery catheter having a proximal end, a central lumen, and a distal end;
- a scaffold stent configured to fit over a portion of the delivery catheter proximate the distal end of the delivery catheter, the scaffold stent having a reduced delivery configuration and an expanded configuration;
- a valve support comprising a frame and a plurality of leaflets attached to the frame, the frame comprising a plurality of struts extending axially from the frame, each strut having a retaining structure at its downstream end, the valve support having a reduced delivery configuration wherein the valve support can be housed within the central lumen of the delivery catheter, wherein the valve support is configured to be delivered independent of the scaffold stent; and
- a grasping member configured to operably attach to the retaining structures of the struts to compress the valve leaflets.
2. The heart valve replacement system of claim 1, further comprising an expandable member proximate the distal end of the delivery catheter, the expandable member configured to expand the scaffold stent.
3. The heart valve replacement system of claim 1, wherein the expandable member comprises a balloon.
4. The heart valve replacement system of claim 1, wherein the scaffold stent is self-expandable, and wherein a retaining mechanism is configured to maintain the scaffold stent in a reduced configuration during delivery.
5. The heart valve replacement system of claim 1, wherein the retaining structures of the struts are attached to the grasping member, the retaining structures couple together to form a sphere-like shape.
6. The heart valve replacement system of claim 1, wherein the delivery catheter has a size of less than or equal to 12 French.
7. The heart valve replacement system of claim 1, wherein the delivery catheter has a size of between 8 French and 12 French.
8. The heart valve replacement system of claim 1, wherein the grasping member comprises a bioptome.
9. The heart valve replacement system of claim 1, wherein the grasping member comprises a snare.
10. The heart valve replacement system of claim 1, wherein the frame of the valve support comprises a shape memory mesh material.
11. The heart valve replacement system of claim 1, comprising a valve skirt attached to a surface of the scaffold stent.
12. The heart valve replacement system of claim 11, wherein the valve skirt comprises a fabric material.
13. The heart valve replacement system of claim 11, wherein the frame of the valve support comprises a generally cylindrical portion, and a flap portion on an upstream end of the frame configured to rest against an upstream end of the scaffold stent, the flap portion configured to minimize or prevent paravalvular regurgitation.
14. The heart valve replacement system of claim 1, comprising at least 3 struts.
15. The heart valve replacement system of claim 1, configured to replace a native aortic valve.
16. A transluminal method of delivering an aortic valve replacement, comprising the steps of:
- providing a delivery catheter carrying a scaffold stent over a distal portion of the delivery catheter, the scaffold stent having an upstream end and a downstream end, the delivery catheter also comprising a valve support having a frame, a plurality of valve leaflets, and a distal flap portion, the valve support carrying a prosthetic aortic valve releasably connected to a delivery cable, the valve support not connected to the scaffold stent;
- positioning the distal end of the delivery catheter in the left ventricle, to position the scaffold stent at the level of the native aortic valve annulus;
- expanding the scaffold stent within the native aortic valve annulus;
- partially moving the valve support out of the delivery catheter, thereby expanding the distal flap portion;
- retracting the valve support such that the distal flap contacts the downstream end of the scaffold stent;
- disconnecting the valve from the delivery cable; and
- withdrawing the delivery catheter and the delivery cable.
17. The method of claim 16, wherein disconnecting the valve from the delivery cable comprises releasing a grasping member connected to retaining structures on distal ends of struts extending from the valve support, whereby release of the bioptome causes the valve leaflets to completely unfold.
18. The method of claim 17, wherein the grasping member comprises a bioptome.
19. The method of claim 16, further comprising the step of securing the valve support to the scaffold stent.
20. The method of claim 19, wherein securing the valve support to the scaffold stent comprises connecting the frame of the valve support to hooks on a radial inwardly-facing surface of the scaffold stent.
Type: Application
Filed: Jun 10, 2015
Publication Date: Oct 1, 2015
Inventors: Gilberto Melnick (Curitiba), Enio Eduardo Guerios (Curitiba)
Application Number: 14/736,037