Patent Application
20230372099
The present invention relates to medical apparatus and methods, and specifically to apparatus and methods for implanting a prosthetic valve at an atrioventricular valve.
The human heart is a muscular organ that pumps deoxygenated blood through the lungs to oxygenate the blood and pumps oxygenated blood to the rest of the body by contractions of four chambers.
After having circulated in the body, deoxygenated blood from the body enters the right atrium through the vena cava(s). In a healthy subject, the right atrium contracts, pumping the blood through the tricuspid valve into the right ventricle. The right ventricle contracts, pumping the blood through the pulmonary semi-lunar valve into the pulmonary artery which splits to two branches, one for each lung. The blood is oxygenated while passing through the lungs, and reenters the heart via the left atrium. The left atrium contracts, pumping the oxygenated blood through the mitral valve into the left ventricle. The left ventricle contracts, pumping the oxygenated blood through the aortic valve into the aorta to be distributed to the rest of the body. The tricuspid valve closes during right ventricle contraction, so that backflow of blood into the right atrium is prevented. Similarly, the mitral valve closes during left ventricle contraction, so that backflow of blood into the left atrium is prevented. The mitral valve and the tricuspid valve are known as atrioventricular valves, each of these valves controlling the flow of blood between an atrium and a ventricle.
In the mitral valve, the mitral annulus defines a mitral valve orifice. An anterior leaflet and a posterior leaflet extend from the mitral annulus. The leaflets are connected by chords to papillary muscles within the left ventricle.
During ventricular diastole, in a healthy subject, the left atrium contracts to pump blood into the left ventricle through the mitral valve orifice. The blood flows through the orifice, pushing the leaflets apart and into the left ventricle with little resistance. In a healthy subject, the leaflets of the aortic valve are kept closed by blood pressure in the aorta.
During ventricular systole, the left ventricle contracts to pump blood into the aorta through the aortic valve, the leaflets of which are pushed open by the blood flow. In a healthy subject, the mitral annulus contracts, pushing the leaflets inwards and reducing the area of the mitral valve orifice by about 20% to 30%. The leaflets coapt to accommodate the excess leaflet surface area, producing a coaptation surface that constitutes a seal. The pressure of blood in the left ventricle pushes against the ventricular surfaces of the leaflets, tightly pressing the leaflets together at the coaptation surface so that a tight, leak-proof seal is formed.
An effective seal of the mitral valve during ventricular systole depends on a sufficient degree of coaptation. Improper coaptation may be caused by any number of physical anomalies that allow leaflet prolapse (for example, elongated or ruptured chords, or weak papillary muscles) or prevent coaptation (for example, short chords, or small leaflets). There are also pathologies that lead to a mitral valve insufficiency, including collagen vascular disease, ischemic mitral regurgitation (resulting, for example, from myocardial infarction, chronic heart failure, or failed/unsuccessful surgical or catheter revascularization), myxomatous degeneration of the leaflets, and rheumatic heart disease. Mitral valve regurgitation leads to many complications including arrhythmia, atrial fibrillation, cardiac palpitations, chest pain, congestive heart failure, fainting, fatigue, low cardiac output, orthopnea, paroxysmal nocturnal dyspnea, pulmonary edema, shortness of breath, and sudden death.
The tricuspid valve includes three leaflets: the septal leaflet, the anterior leaflet, and the posterior leaflet. Each of the valve leaflets is attached to the tricuspid valve annulus, which defines the tricuspid valve orifice. The leaflets are connected to papillary muscles within the right ventricle, by chords. In a healthy subject the tricuspid valve controls the direction of blood flow from the right atrium to the right ventricular, in a similar manner to the control of the mitral valve over the direction of blood flow on the left side of the heart. During ventricular diastole, the tricuspid valve opens, such as to allow the flow of blood from the right atrium to the right ventricle, and during ventricular systole the leaflets of the tricuspid valve coapt, such as to prevent the backflow of blood from the right ventricle to the right atrium.
Tricuspid valve regurgitation occurs when the tricuspid valve fails to close properly. This can cause blood to flow back up into the right atrium when the right ventricle contracts. Tricuspid valve regurgitation is most commonly caused by right ventricle dilation, which leads to the tricuspid valve annulus dilating, resulting in the valve leaflets failing to coapt properly.
In accordance with some applications of the present invention, a prosthetic mitral valve frame includes a valve-frame body that defines a ventricular portion (which upon deployment is configured to be disposed within the subject's left ventricle), and an atrial portion (which upon deployment is configured to be disposed within the subject's left atrium). A prosthetic mitral valve, which typically includes a plurality of leaflets (e.g., two leaflets, or three leaflets, as shown), is typically sutured or otherwise coupled to the valve-frame body. Typically, in a non-constrained configuration of the prosthetic mitral valve frame, the first and second sets of chord-recruiting arms extend radially from a portion of the valve-frame body that is configured to be placed within the subject's ventricle. For some applications, the chord-recruiting arms are configured to extend axially from a ventricular end of the valve-frame body (i.e., the end of the valve-frame body that is configured to be placed within the ventricle) toward an atrial end of the valve-frame body (i.e., the end of the valve-frame body that is configured to be placed within the atrium). Typically, each of the first and second sets of chord-recruiting arms curves around the outside of the valve-frame body in a respective, different circumferential direction of curvature. For example, the first set may curve in the counterclockwise direction and the second set in the clockwise direction, or vice versa. For some applications, the arms belonging to the first set of chord-recruiting arms are configured to have concavely rounded leading edges facing in the first circumferential direction, and the arms belonging to the second set of chord-recruiting arms are configured to have concavely rounded leading edges facing in the second circumferential direction.
Typically, the prosthetic mitral valve and the prosthetic mitral valve frame are delivered to the native mitral valve, using a delivery catheter, and the delivery catheter is configured to maintain the prosthetic mitral valve and prosthetic mitral valve frame in radially-constrained configurations (i.e., “crimped” configurations) during the delivery. When the distal end of the delivery catheter is disposed within the subject's left ventricle, the first set of the chord-recruiting arms are allowed to assume non-radially-constrained configurations and at least partially radially expand. Subsequent to the first set of chord-recruiting arms being deployed among chords of the native mitral valve (and, typically, while the chord-recruiting arms belonging to the other set of chord-recruiting arms are maintained in radially-constrained configurations by the delivery catheter), at least a portion of the valve frame is rotated in the same circumferential direction as the direction of the circumferential curvature of the chord-recruiting arms belonging to the first set. For some applications, the rotation of the first set of chord-recruiting arms is such as to cause the first set of chord-recruiting arms to (a) pull the native mitral valve radially inward toward the valve frame, and (b) twist the native mitral valve around the valve frame, by recruiting and deflecting at least a portion of the chords.
Typically, either prior or subsequent to the above-described first rotation step being performed, the second set of chord-recruiting arms are allowed to assume non-radially-constrained configurations and at least partially radially expand. Further typically, subsequent to the first rotation step having been performed, the valve frame is rotated in the same circumferential direction as the direction of the circumferential curvature of the second set of the chord-recruiting arms. Typically, the rotation of the valve frame in this manner causes chords of the native mitral valve to become entangled between the two sets of chord-recruiting arms, which strengthens the anchoring of the prosthetic mitral valve frame to the native mitral valve apparatus, relative to if the prosthetic mitral valve frame only included a single set of chord-recruiting arms that curve in a single circumferential direction. Typically, the angle through which the valve frame is rotated in the second rotation step is less than or equal to the angle through which the valve frame is rotated in the second rotation step, in order to prevent chords from tearing.
Subsequent to both sets of chord-recruiting arms having been released and the valve frame having been rotated in first and second circumferential directions, the valve-frame body is allowed to assume its non-radially-constrained configurations. Typically, by the valve-frame body assuming its non-radially-constrained configurations, the valve-frame body is configured to trap the native valve leaflets in a partially closed and twisted configuration, to thereby at least partially seal a space between the native mitral valve and the prosthetic mitral valve.
The term “distal” and related terms, when used with reference to a device or a portion thereof, should be interpreted to mean an end of the device or the portion thereof that, when inserted into a subject's body, is typically further from the location through which the device is inserted into the subject's body. The term “proximal” and related terms, when used with reference to a device or a portion thereof, should be interpreted to mean an end of the device or the portion thereof that, when inserted into a subject's body, is typically closer to the location through which the device is inserted into the subject's body.
There is therefore provided, in accordance with some applications of the present invention, apparatus for use with a prosthetic valve that is configured to be deployed within a native atrioventricular valve of a heart of a mammalian subject, the native atrioventricular valve including a valve annulus, valve leaflets, chords, and papillary muscles, the apparatus comprising:
In some applications, the first set of chord-recruiting arms are configured to extend radially from the valve-frame body.
In some applications, the first set of chord-recruiting arms are configured to extend axially from a ventricular end of the valve-frame body to an atrial end of the valve frame body.
In some applications, the second set of chord-recruiting arms are configured to extend radially from the valve-frame body.
In some applications, the second set of chord-recruiting arms are configured to extend axially from a ventricular end of the valve-frame body to an atrial end of the valve frame body.
In some applications, the valve frame is configured such that rotating the valve frame in the first circumferential direction causes the first set of chord-recruiting arms to (a) pull the native atrioventricular valve radially inward toward the valve frame, and (b) twist the native atrioventricular valve around the valve frame, by recruiting and deflecting at least a portion of the chords of the native atrioventricular valve.
In some applications, the valve frame is configured such that rotating the valve frame in the first circumferential direction subsequent to the valve frame being rotated in the first direction causes cause the chords to become entangled between the first and second sets of chord-recruiting arms.
In some applications, the valve-frame body is configured to radially expand, such as to trap the leaflets of the native atrioventricular valve in a partially closed and twisted configuration, to thereby at least partially seal a space between the native atrioventricular valve and the prosthetic valve.
There is further provided, in accordance with some applications of the present invention, a method for use with a prosthetic valve that is configured to be deployed within a native atrioventricular valve of a heart of a mammalian subject, the native atrioventricular valve including a valve annulus, valve leaflets, chords, and papillary muscles, the method including:
In some applications, the method further includes causing the valve-frame body to radially expand, such as to trap the leaflets of the native atrioventricular valve in a partially closed and twisted configuration, to thereby at least partially seal a space between the native atrioventricular valve and the prosthetic valve.
In some applications, deploying the first set of chord-recruiting arms such that the first set of chord-recruiting arms become deployed among chords of the native atrioventricular valve includes deploying the first set of chord-recruiting arms such that the first set of chord-recruiting arms extend radially from the valve-frame body.
In some applications, deploying the first set of chord-recruiting arms such that the first set of chord-recruiting arms become deployed among chords of the native atrioventricular valve includes deploying the first set of chord-recruiting arms such that the first set of chord-recruiting arms extend axially from a ventricular end of the valve-frame body to an atrial end of the valve frame body.
In some applications, deploying the second set of chord-recruiting arms such that the second set of chord-recruiting arms become deployed among chords of the native atrioventricular valve includes deploying the second set of chord-recruiting arms such that the second set of chord-recruiting arms extend radially from the valve-frame body.
In some applications, deploying the first set of chord-recruiting arms such that the second set of chord-recruiting arms become deployed among chords of the native atrioventricular valve includes deploying the second set of chord-recruiting arms such that the second set of chord-recruiting arms extend axially from a ventricular end of the valve-frame body to an atrial end of the valve frame body.
In some applications, deploying the second set of chord-recruiting arms such that the second set of chord-recruiting arms become deployed among chords of the native atrioventricular valve includes deploying the second set of chord-recruiting arms such that the second set of chord-recruiting arms become deployed among chords of the native atrioventricular valve subsequent to rotating the portion of the valve frame in the first circumferential direction.
In some applications, deploying the second set of chord-recruiting arms such that the second set of chord-recruiting arms become deployed among chords of the native atrioventricular valve includes deploying the second set of chord-recruiting arms such that the second set of chord-recruiting arms become deployed among chords of the native atrioventricular valve prior to rotating the portion of the valve frame in the first circumferential direction.
In some applications, rotating at least the portion of the valve frame in the second circumferential direction includes rotating the portion of the valve frame in the second circumferential direction through an angle that is less than an angle through which the portion of the valve frame is rotated during the rotation of the portion of the valve frame in the first circumferential direction.
In some applications, rotating at least the portion of the valve frame in the second circumferential direction includes rotating the portion of the valve frame in the second circumferential direction through an angle that is equal to an angle through which the portion of the valve frame is rotated during the rotation of the portion of the valve frame in the first circumferential direction.
There is further provided, in accordance with some applications of the present invention, apparatus for use with a prosthetic valve that is configured to be deployed within a native atrioventricular valve of a heart of a mammalian subject, the native atrioventricular valve including a valve annulus, valve leaflets, chords, and papillary muscles, the apparatus including:
In some applications, the delivery device is configured to cause the valve-frame body to radially expand, such as to trap the leaflets of the native atrioventricular valve in a partially closed and twisted configuration, to thereby at least partially seal a space between the native atrioventricular valve and the prosthetic valve.
In some applications, the first set of chord-recruiting arms are configured to extend radially from the valve-frame body.
In some applications, the first set of chord-recruiting arms are configured to extend axially from a ventricular end of the valve-frame body to an atrial end of the valve frame body.
In some applications, the second set of chord-recruiting arms are configured to extend radially from the valve-frame body.
In some applications, the second set of chord-recruiting arms are configured to extend axially from a ventricular end of the valve-frame body to an atrial end of the valve frame body.
In some applications, the delivery device is configured to deploy the second set of chord-recruiting arms such that the second set of chord-recruiting arms become deployed among chords of the native atrioventricular valve, subsequent to rotating the portion of the valve frame in the first circumferential direction.
In some applications, the delivery device is configured to deploy the second set of chord-recruiting arms such that the second set of chord-recruiting arms become deployed among chords of the native atrioventricular valve, prior to rotating the portion of the valve frame in the first circumferential direction.
In some applications, the delivery device is configured to rotate at least the portion of the valve frame in the second circumferential direction through an angle that is less than an angle through which the portion of the valve frame is rotated during the rotation of the portion of the valve frame in the first circumferential direction.
In some applications, the delivery device is configured to rotate at least the portion of the valve frame in the second circumferential direction through an angle that is equal to an angle through which the portion of the valve frame is rotated during the rotation of the portion of the valve frame in the first circumferential direction.
The present invention will be more fully understood from the following detailed description of applications thereof, taken together with the drawings, in which:
Reference is now made to
Typically, valve frame 22 is made of a shape-memory material (e.g., a shape-memory alloy, such as nitinol and/or copper-aluminum-nickel), which is covered on one or both sides with a covering material 32, e.g., a fabric and/or a polymer (such as expanded polytetrafluoroethylene (ePTFE), or woven, knitted and/or braided polyester). Typically, the shape-memory material of valve frame is shaped into a stent-like structure that comprises struts and/or cells of the shape-memory material. The covering material is typically coupled to the shape-memory material via stitches.
Typically, in a non-constrained configuration of prosthetic mitral valve frame 22, first and second sets of chord-recruiting arms 34 extend radially from a portion of valve-frame body 24 that is configured to be placed within the subject's ventricle. For some applications, each of the sets of chord-recruiting arms includes a plurality of chord-recruiting arms, for example, more than 2 (e.g., more than 4), and/or fewer than 15 (e.g., fewer than 8), e.g., 2-15 or 4-8 chord-recruiting arms. Typically, the chord-recruiting arms are configured to extend radially from the valve-frame body, in addition to extending axially from a ventricular end of the valve-frame body (i.e., the end of the valve-frame body that is configured to be placed within the ventricle) toward an atrial end of the valve-frame body (i.e., the end of the valve-frame body that is configured to be placed within the atrium). Further typically, each of the first and second sets of chord-recruiting arms curves around the outside of the valve-frame body in a respective, different circumferential direction of curvature. For example, the first set may curve in the counterclockwise direction and the second set in the clockwise direction, or vice versa. For some applications, the arms belonging to the first set of chord-recruiting arms are configured to have concavely rounded leading edges facing in the first circumferential direction, and the arms belonging to the second set of chord-recruiting arms are configured to have concavely rounded leading edges facing in the second circumferential direction.
Typically, prosthetic mitral valve 20 and prosthetic mitral valve frame 22 are delivered to the native mitral valve, using a delivery catheter 40 (shown in the right portion of
Reference is now made to
As shown in
As shown in
As shown in
As described hereinabove, the chord-recruiting arms belonging to the distal set are typically shape set such that the circumferential curvature of the chord-recruiting arms belonging to the distal set is in the opposite circumferential direction from that of the chord-recruiting arms belonging to the proximal set. For example, as shown in
Subsequent to both sets of chord-recruiting arms having been released and the valve frame having been rotated in first and second circumferential directions, the valve-frame body (i.e., ventricular portion 26 and atrial portion 28 of the valve frame) is allowed to assume its non-radially-constrained configurations. For some applications, the atrial portion is allowed to assume its non-radially-constrained configuration by releasing the atrial portion from the delivery catheter, e.g., by further retracting proximal covering sheath 42. For some applications, the ventricular portion is allowed to assume its non-radially-constrained configuration by releasing the ventricular portion from the delivery catheter, e.g., by further advancing distal nose cone 44.
Reference is now made to
Typically, prosthetic mitral valve 20 and prosthetic mitral valve frame 22 are delivered to the native mitral valve, using a delivery catheter 40 (shown in
When the distal end of the delivery catheter is disposed within the left ventricle, a first set of the chord-recruiting arms 34 are allowed to assume non-radially-constrained configurations and at least partially radially expand, as shown in
As shown in
As shown in
As described hereinabove, the chord-recruiting arms belonging to the proximal set are typically shape set such that the circumferential curvature of the chord-recruiting arms belonging to the proximal set is in the opposite circumferential direction from that of the chord-recruiting arms belonging to the distal set. For example, as shown in
Subsequent to both sets of chord-recruiting arms having been released and the valve frame having been rotated in first and second circumferential directions, the valve-frame body (i.e., ventricular portion 26 and atrial portion 28 of the valve frame) is allowed to assume its non-radially-constrained configuration. For some applications, the atrial portion is allowed to assume its non-radially-constrained configuration by releasing the atrial portion from the delivery catheter, e.g., by further retracting proximal covering sheath 42. For some applications, the ventricular portion is allowed to assume its non-radially-constrained configuration by releasing the ventricular portion from the delivery catheter, e.g., by further advancing distal nose cone 44.
Although in the examples described herein the proximal set of arms curve in the counterclockwise circumferential direction (and the corresponding rotation of the valve frame is in this direction), and the distal set of arms curve in the clockwise circumferential direction (and the corresponding rotation of the valve frame is in this direction), the scope of the present invention includes the proximal set of arms curving in the clockwise circumferential direction (and the corresponding rotation of the valve frame is in this direction), and the distal set of arms curve in the counterclockwise circumferential direction (and the corresponding rotation of the valve frame is in this direction). Similarly, the scope of the present invention includes the first and second sets of arms being disposed at the same height as each other along the valve frame, or overlapping with each other along the valve frame, alternating with each other along the valve frame, and/or other possible configurations.
The scope of the present invention includes a valve frame that is generally as described herein, but having proximal and distal sets of arms both of which curve in the same direction as each other. Typically, the arms and methods of use therewith are generally as described hereinabove, mutatis mutandis. For some such applications, each of the sets of arms is configured to be deployed among chords at a respective, different height within the left ventricle. The arms are used to recruit and deflect the shapes of chords in the manner described hereinabove, at respective, different heights within the left ventricle. Alternatively, during a procedure, only one of the sets of arms may be selected to be deployed among chords and to be used to recruit and deflect the shapes of chords, while the other set of arms may be released from the delivery catheter only when the ventricular portion of the valve frame is released (such that the other set of arms does not become deployed among chords). Typically, the selection of which set of arms to be deployed among the chords is performed by a medical professional, based upon anatomical constraints of the particular patient within whom the valve frame is deployed.
Although some applications of the present invention are described as being utilized in conjunction with a prosthetic mitral valve and a prosthetic mitral valve frame, the scope of the present invention includes using generally similar apparatus and techniques with any prosthetic atrioventricular valve and prosthetic atrioventricular valve frame. Thus, the scope of the present invention includes using generally similar apparatus and techniques with a prosthetic tricuspid valve and prosthetic tricuspid valve frame having a generally similar configuration to the prosthetic mitral valve and the prosthetic mitral valve frame described herein, mutatis mutandis. For example, a prosthetic tricuspid valve frame that includes a first and second sets of chord-recruiting arms may be delivered to a subject's native tricuspid valve via the subject's right atrium, using delivery catheter 40. Typically, the first and second sets of chord-recruiting arms are shape set such as to extend radially from the valve-frame body, in addition to extending axially from a ventricular end of the valve-frame body (i.e., the end of the valve-frame body that is configured to be placed within the ventricle) toward an atrial end of the valve-frame body (i.e., the end of the valve-frame body that is configured to be placed within the atrium). Further typically, each of the first and second sets of chord-recruiting arms curves around the outside of the valve-frame body in a respective, different circumferential direction of curvature. For example, the first set may curve in the counterclockwise direction and the second set in the clockwise direction, or vice versa.
Typically, chord-recruiting arms belonging to the first set of chord-recruiting arms are allowed to deploy among chords of the native tricuspid valve, by assuming their non-radially constrained configurations, and the valve frame is rotated in the same circumferential direction as the direction of circumferential curvature of the first set of chord-recruiting arms. Typically, this causes the chord-recruiting arms to (a) pull the native tricuspid valve radially inward toward the valve frame, and (b) twist the native tricuspid valve around the valve frame, by recruiting and deflecting at least a portion of the chords. For some applications, the second set of the chord-recruiting arms are allowed to assume non-radially-constrained configurations and at least partially radially expand, such as to become deployed among chords of the native tricuspid valve. As described hereinabove, the chord-recruiting arms belonging to the second set are typically shape set such that the circumferential curvature of the chord-recruiting arms belonging to the second set is in the opposite circumferential direction from that of the chord-recruiting arms belonging to the first set. Subsequent to the first rotation step having been performed, the valve frame is rotated in the same circumferential direction as the direction of the circumferential curvature of the second set of the chord-recruiting arms. Typically, the rotation of the valve frame in this manner causes chords of the native tricuspid valve to become entangled between the two sets of chord-recruiting arms, which strengthens the anchoring of the prosthetic tricuspid valve frame to the native tricuspid valve apparatus, relative to if the prosthetic tricuspid valve frame only included a single set of chord-recruiting arms that curve in a single circumferential direction.
Subsequent to both sets of chord-recruiting arms having been released and the valve frame having been rotated in first and second circumferential directions, the valve-frame body is allowed to assume its non-radially-constrained configuration. Typically, by the valve-frame body assuming its non-radially-constrained configuration, the valve-frame body is configured to trap the native tricuspid valve leaflets in a partially closed and twisted configuration, to thereby at least partially seal a space between the native tricuspid valve and the prosthetic valve. For example, the ventricular portion may be configured to radially expand such as to trap the native valve leaflets between the ventricular portion and the chord-recruiting arms, and/or the atrial portion may be configured to radially expand such as to trap the native valve leaflets between the atrial portion and the chord-recruiting arms. Further typically, the valve frame is anchored to the native tricuspid valve apparatus by chords being entangled between arms belonging to the first and second sets of chord-recruiting arms.
It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described hereinabove, as well as variations and modifications thereof that are not in the prior art, which would occur to persons skilled in the art upon reading the foregoing description.
The present application claims priority from U.S. Provisional Patent Application 63/106,034 to Orlov, filed Oct. 27, 2020, entitled “Atrioventricular valve frame with opposing sets of arms,” which is incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2021/059799 | 10/24/2021 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63106034 | Oct 2020 | US |
