The present disclosure relates to heart valve interventional systems and methods and, more particularly, to methods for delivering and repositioning mitral valves.
Human heart valves, which include the aortic, pulmonary, mitral and tricuspid valves, function in synchronization with the pumping heart to control the flow of blood between chambers of the heart. In short, the valves allow blood to flow downstream and inhibit blood from flowing upstream. Diseased heart valves exhibit impairments such as narrowing of the valve, remodeling of the annulus, or calcification, which inhibit the valves from properly controlling blood flow. Such impairments reduce the heart's blood-pumping efficiency and can be a debilitating or, in some situations, life threatening. Thus, extensive efforts have been made to develop methods and devices to repair or replace impaired heart valves.
One technique for addressing a damaged or defective heart valve is to replace the native valve with a valve prosthesis. One category of heart valve prosthesis includes those that can be delivered in a minimally invasive fashion so as to minimize trauma to the patient. Replacement valves are being designed to be delivered through minimally invasive procedures and even percutaneous procedures. Such replacement valves often include a tissue-based valve that is connected to an expandable frame that is then delivered to the native valve's annulus.
Development of prostheses including but not limited to replacement heart valves that can be collapsed for minimally invasive delivery and then controllably expanded has proven to be particularly challenging. An additional challenge relates to the ability of such prostheses to be secured relative to adjacent native tissue. Adequate anchoring of the prosthesis is important to ensuring the successful operation of the prosthetic heart valve for a sufficient length of time.
The present disclosure describes shapes and geometries of anchoring elements, including feet, used to secure a prosthetic valve, e.g., a prosthetic mitral valve, in the native heart valve annular position. In embodiments, the foot geometry/directionality is designed such that the foot loads to the fibrous annular region that is made of collagenous tissue with higher puncture resistance. Additionally, the foot contact surface area is designed such that the pressure exerted by the foot is below the pressure required to puncture the heart tissue, such as the left ventricular (LV) muscle wall. Further, the present disclosure provides an improved method of delivering and/or repositioning a valve dock and/or valve replacement system by inverting the implant anchors, e.g., including the feet, to point downward, i.e., toward the ventricle, while crossing the native mitral valve annulus. The valve feet are then deployed once the tips of the feet are a sufficient distance past the annulus. To reposition the valve, the frame is retracted using delivery mechanisms to return the feet to the inverted state, which can be used for removing and/or reattempting deployment of the valve.
As recited in examples, Example 1 is a method of delivering a valve prosthesis to be deployed within a native heart valve at a native heart valve annulus. The method including collapsing a prosthetic valve having an expandable frame comprising a proximal end and a distal end and a longitudinal axis extending therethrough inside of a delivery instrument, such that a plurality of spaced anchors extending from the distal end of the expandable frame towards the proximal end are collapsed to an inverted position in a collapsed anchor configuration. The method further including advancing the delivery instrument a first distance such that the plurality of spaced anchors extend below the valve annulus, and releasing each of the plurality of spaced anchors such that each of the plurality of spaced anchors is repositioned from the inverted position to an expanded anchor configuration to contact a subannular location
Example 2 is the method of Example 1, comprising adjusting an angle of each of the plurality of spaced anchors, such that upon release the spaced anchors contact the subannular location.
Example 3 is the method of Example 1, where releasing each of the plurality of spaced anchors includes releasing each of the plurality of spaced anchors such that each of the plurality of spaced anchors has a foot angle of from 0 to 45 degrees relative to the longitudinal axis.
Example 4 is the method of Example 1, wherein collapsing the prosthetic valve includes collapsing the plurality of spaced anchors to the collapsed anchor configuration, such that each of the plurality of spaced anchors pivots to an outward and progressively downward position.
Example 5 is the method of Example 1, wherein collapsing the prosthetic valve includes collapsing the plurality of spaced anchors such that each of the plurality of spaced anchors pivots from a foot angle of from 0 to 45 degrees to an outward and downward foot angle of from 45 to 180 degrees.
Example 6 is the method of Example 1, wherein the delivery instrument includes an outer catheter member attached to the expandable frame adjacent the proximal end and an inner catheter member attached to the expandable frame adjacent the distal end.
Example 7 is the method of Example 6, wherein collapsing the prosthetic valve includes retracting the inner catheter member into the outer catheter member to pivot each of the plurality of spaced anchors to an outward and progressively downward position.
Example 8 is the method of Example 6, wherein releasing each of the plurality of spaced anchors includes extending the inner catheter member out of the outer catheter member to pivot each of the plurality of spaced anchors to the expanded anchor configuration.
Example 9 is the method of Example 1, wherein each of the plurality of spaced anchors are locked into the collapsed anchor configuration prior to advancing the delivery instrument.
Example 10 is the method of Example 1, comprising at least one of repositioning and removing the valve prosthesis by collapsing the prosthetic valve, such that each of the plurality of spaced anchors collapses to the inverted position.
Example 11 a method of delivering a valve prosthesis to be deployed within a native heart valve at a native heart valve annulus. The method including collapsing a prosthetic valve having an expandable frame comprising a proximal end and a distal end and a longitudinal axis extending therethrough inside of a delivery instrument, such that a plurality of spaced anchors extending from the distal end of the expandable frame towards the proximal end pivot outward and downward from an expanded foot angle of from 0 to 45 degrees to a collapsed foot angle of from 45 to 180 degrees. The method further including advancing the delivery instrument such that the plurality of anchors extend below the valve annulus, and releasing each of the plurality of anchors such that each of the plurality of anchors pivots to the expanded foot angle of from 0 to 45 degrees.
Example 12 is the method of Example 11, where releasing each of the plurality of anchors repositions the anchors for contacting subannular tissue.
Example 13 is the method of Example 11, wherein the delivery instrument includes an outer catheter member attached to the expandable frame adjacent the proximal end and an inner catheter member attached to the expandable frame adjacent the distal end.
Example 14 is the method of Example 13, wherein collapsing the prosthetic valve includes retracting the inner catheter member into the outer catheter member to pivot each of the plurality of anchors to an inverted position.
Example 15 is the method of Example 13, wherein releasing each of the plurality of anchors includes extending the inner catheter member out of the outer catheter member to pivot each of the plurality of anchors to the expanded foot angle for contacting subannular tissue.
Example 16 is a valve prosthesis system including a prosthetic valve and a delivery instrument. The prosthetic valve having an expandable frame including a proximal end and a distal end and a longitudinal axis extending therethrough. The expandable frame configured to collapse radially for delivery and expand radially upon deployment to an expanded configuration. The prosthetic valve including a plurality of anchors extending from the distal end of the expandable frame towards the proximal end, each anchor being expandable from a collapsed anchor configuration to an expanded anchor configuration. The delivery instrument includes an outer catheter member attached to the expandable frame adjacent the proximal end and an inner catheter member attached to the expandable frame adjacent the distal end, wherein the inner catheter member is retracted into the outer catheter member to pivot each of the plurality of anchors to an inverted position in the collapsed anchor configuration.
Example 17 is the system of Example 16, wherein the delivery instrument is configured to release each of the plurality of anchors from the inverted position to the expanded anchor configuration.
Example 18 is the system of Example 16, wherein the inner catheter member is retracted into the outer catheter member to pivot each of the plurality of anchors outward and progressively downward to the inverted position.
Example 19 is the system of Example 16, wherein the inner catheter member is retracted into the outer catheter member to pivot each of the plurality of anchors from a foot angle of from 0 to 45 degrees to a foot angle of from 45 to 180 degrees.
Example 20 is the system of Example 16, wherein the inner catheter member is extended out of the outer catheter member to pivot each of the plurality of anchors to the expanded anchor configuration
While multiple embodiments are disclosed, still other embodiments of the present disclosure will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the disclosure. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.
While the disclosure is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the disclosure to the embodiments described. On the contrary, the disclosure is intended to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure as defined by the appended claims.
The prosthesis 100 includes an anchor assembly 102 and a valve assembly 104. In some embodiments, the occluding function of the prosthesis 100 can be performed using configurations other than the depicted tri-leaflet occluder. For example, bi-leaflet, quad-leaflet, or mechanical valve constructs can be used in some embodiments.
The anchor assembly 102 includes an expandable frame 106 having a proximal end 108 and a distal end 110 with a longitudinal axis 112 extending therethrough. The expandable frame 106 is configured to collapse radially for delivery and expand radially upon deployment to the expanded configuration.
The anchor assembly 102 includes a plurality of spaced anchors 114a-114d extending from the distal end 110 of the expandable frame 106 towards the proximal end 108. Each of the anchors 114a-114d includes a free end or foot 116.
As shown in
The heart valve prosthesis 100 includes four anchors 114a-114d, such that two of the anchors 114a and 114d are generally disposed at the anchor locations 202a and 202d, respectively, in the anterior region 204 and two of the anchors 114b and 114c are generally disposed at the anchor locations 202b and 202c, respectively, in the posterior region 206. In embodiments, the heart valve prosthesis 100 can include three anchors, two of which are generally disposed in the anterior region 204 and one of which is disposed in a generally central location of the posterior region 206. In other embodiments, the heart valve prosthesis 100 can include more than three or four anchors.
In some embodiments, the heart valve prosthesis 100 design and configuration are any one of the prosthesis designs and configurations disclosed in United States Patent Application Publication No. 2017/0189177 or United States Patent Application Publication No. 2019/0029814, which are both hereby incorporated by reference herein in their entirety. While the concepts disclosed herein may be used in conjunction with any heart valve, the following disclosure provides embodiments for a mitral valve prosthesis.
While the anchor locations 202a-202d are illustrated in certain locations around the circumference of the prosthetic mitral valve annulus 200 in
By disposing the anchors 114a-114d at appropriate locations about the circumference of the annulus 200, the heart valve prosthesis 100 is adequately anchored such that during diastole, when the left ventricle contracts and the blood pressure drives the valve prosthesis toward the left atrium, the anchors 114a-114d contact subannular tissue, i.e., tissue below the annulus of the native heart valve, and thereby anchor the prosthesis 100 at the mitral valve annulus location.
The annulus 302 is made up of fibrous tissue, such as collagen and/or reticular fibers, which have significantly high puncture resistance. The LV muscle substrate 306 is made up of cardiac muscle cells that have a somewhat lower puncture resistance as compared to the annulus 302. In embodiments, the prosthetic valve anchors 114a-114d load to the tissue of the annulus 302, the LV muscle 306, or the transition region 304.
The anchors 402 and the feet 404 are configured to contact the subannular tissue on the ventricular side of the valve annulus. As shown in
In some embodiments, the foot geometry is designed to ensure that the foot contact surface area 414 is such that the maximum pressure exerted by the foot is less than the puncture resistance of the substrate, i.e., the native heart valve tissue contacted by the foot of the prosthesis. Where, the foot geometry and the foot contact surface area 414 are based on multiple items, such as the foot angle, the arc length of the foot, the arc radius of the foot, and the foot width, which can be adjusted to ensure that the maximum pressure exerted by the foot is less than the puncture resistance of the substrate. In addition, the contact surface area 414 can be adjusted or controlled by modifying the profile of the foot at the contact location, as illustrated in
Also, addition of the diamond-like structures in iterations B-E, as compared to only increasing the strut width, allows for easier formability and manufacturability of these parts as well as improved deliverability.
By adjusting variables including one or more of the locations of the anchors, the number of anchors, the number of feet, the number of feet per anchor, foot angles, foot widths, arc length, and arc radius, the transfer forces and puncture pressures generated by the prosthetic valve may be increased or decreased. Where, in embodiments, a primary function of the foot is to provide stable anchoring to the native heart valve without puncturing into the loading tissue, i.e., the substrate, of the heart. Also, in embodiments, the optimized foot locations in combination with the foot geometry ensure that the foot does not puncture into or through the substrate.
In
The delivery system 802 includes an outer catheter member 818 attached to the proximal end 808 of the prosthetic heart valve 800 adjacent the heart valve implant arches 806 and an inner catheter member 820 attached to the hub 810 at the distal end 812 of the prosthetic heart valve 800. In this configuration, the anchoring projections 804 including the feet 816 point upward. In embodiments, the number of anchoring projections 804 and/or elongated LV frame members 814 vary from two to nine. The elongated LV frame member's length, stiffness, angle relative to the feet 816 and the hub 810, and curvature facilitate the inversion angle of the feet 816. In embodiments, the delivery system 802 facilitates inversion of the prosthetic heart valve 800 through a flexible inner catheter member 820 at the hub 810 and a rigid outer catheter member 818 at the implant arches 806. In embodiments, the outer catheter member 818 is connected to the prosthetic heart valve 800 at other frame locations to further facilitate the inversion geometry.
Thus, the anchoring projections 804 and the feet 816 pivot outward and progressively downward from the expanded configuration foot angles of 0 to 45 degrees to the collapsed configuration foot angles of between 45 and 180 degrees as the inner catheter member 820 is retracted into the outer catheter 818. Once the desired inverted delivery geometry is achieved the inner catheter member 820 is locked in position relative to the outer catheter member 818.
This inverted delivery technique allows for a prosthetic heart valve 800 having a 0 degree foot angle, i.e., a foot oriented generally parallel to the longitudinal axis of the prosthetic heart valve 800, to be easily delivered. Further, the inverted delivery technique enables reduced delivery depth since the feet 816 are facing forward and only the feet 816 cross the native valve annulus as opposed to each of the hub 810, the elongated LV frame member 814, and the implant arches 306 or other components of the prosthetic heart valve 800. This inverted technique also allows for improved repositioning as the prosthetic heart valve 800 can be retracted into the delivery catheter system 802 to invert back the feet 816 and redeliver the prosthetic heart valve 800. Further, this technique allows for a reduction in imaging intensity.
Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the present disclosure. For example, while the embodiments described above refer to particular features, the scope of this disclosure also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Accordingly, the scope of the present disclosure is intended to embrace all such alternatives, modifications, and variations as fall within the scope of the claims, together with all equivalents thereof.
Filing Document | Filing Date | Country | Kind |
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PCT/US2020/032230 | 5/8/2020 | WO | 00 |
Number | Date | Country | |
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62845857 | May 2019 | US |