Prosthetic mitral valve with anchoring device

BACKGROUND

0001Complications of the mitral valve, which controls the flow of blood from the left atrium into the left ventricle of the human heart, have been known to cause fatal heart failure. In the developed world, one of the most common forms of valvular heart disease is mitral valve leak, also known as mitral regurgitation, which is characterized by the abnormal leaking of blood from the left ventricle through the mitral valve and back into the left atrium. This occurs most commonly due to ischemic heart disease when the leaflets of the mitral valve no longer meet or close properly after multiple infarctions, idiopathic and hypertensive cardiomyopathies where the left ventricle enlarges, and with leaflet and chordal abnormalities, such as those caused by a degenerative disease.

0002In addition to mitral regurgitation, rheumatic disease can lead to mitral narrowing or stenosis. While this has been virtually eliminated in developed countries, it is still common where the quality of living is not as high.

0003In the course of the last decade many companies have been successful in creating catheter or minimally invasive implantable aortic valves, but such implantation of a mitral valve is more difficult. Patients would be benefited by implanting a device by a minimally invasive surgical procedure employing a small incision or by a catheter implantation such as from the groin. From the patient's point of view, the catheter procedure is very attractive. Many patients who require mitral valve replacement are elderly and an open heart procedure is painful, risky and takes time for recovery. Some patients are not even candidates for such a surgery due to their advanced age and frailty.

0004<patcit id="pcit0001" dnum="US20130310928A1"><text>US 2013/0310928 A1</text></patcit> discloses prosthetic heart valve devices for percutaneous replacement of native heart valves and associated systems. A prosthetic heart valve device can include an expandable support having an outer surface and configured for placement between leaflets of the native valve. The device can also include a plurality of asymmetrically arranged arms coupled to the expandable support and configured to receive the leaflets of the native valve between the arms and the outer surface. The arms can include tip portions for engaging a subannular surface of the native valve. Reference is further made to <patcit id="pcit0002" dnum="US20110245911A1"><text>US 2011/0245911 A1</text></patcit>, <patcit id="pcit0003" dnum="US20130310917A1"><text>US 2013/0310917 A1</text></patcit>, and <patcit id="pcit0004" dnum="US20110208297A1"><text>US 2011/0208297 A1</text></patcit>.

SUMMARY

0005Previous filings (for example, International <patcit id="pcit0005" dnum="WO2013114214A"><text>PCT Publication No. WO 2013/114214</text></patcit>) have provided a disclosure on the use of an anchor to attach a mitral valve prosthesis in a patient via a catheter or minimally invasive procedure. The anchor most commonly described in these disclosures is a helical anchor which is first placed near the native mitral valve annulus and then the prosthetic valve is implanted inside the anchor. It would also be possible to add a helical anchor after the prosthetic valve was placed. The helical anchor can be placed to improve the stability of the prosthesis, to prevent rocking or even to control a leak that occurs around the valve. Whether the anchor is placed before or after the valve implant, this creates a two-step procedure for the interventionalist. He or she must first place the anchor, and then place the prosthetic valve, or vice versa.

0006It would be useful to have devices and methods to combine the anchor delivery with the valve delivery to simplify the procedure. A single surgical procedure can also reduce the impact on the patient.

0007The present disclosure provides a delivery device and system for delivering a prosthetic mitral valve and an anchoring device, such as a helical anchoring device, and methods thereof. The prosthetic mitral valve and the helical anchoring device can be contained within a catheter that delivers both the prosthetic mitral valve and the helical anchoring device to a mitral position of a patient in a single procedure.

0008The present invention is defined by the appended claims. According to an embodiment of the invention, a mitral valve prosthesis includes an expandable valve frame and a plurality of arms each connected to the valve frame at or near a first end of the valve frame. A first arm from among the plurality of arms has a shape that is different from a shape of each of the other arms. The first arm is configured to guide a helical anchoring device around the valve frame.

0009The first arm can have a first end attached to the valve frame and a second end configured to extend farther radially from a central axis of the valve frame than the valve frame extends from the central axis when the valve frame is in an expanded configuration. According to the present invention, the mitral valve prosthesis comprises an anchoring device including a coil that defines an inner space. The valve frame is held by the anchoring device when the valve frame is in the expanded configuration in the inner space of the coil.

0010According to an illustrative example, a method (not forming part of the present invention) for delivering a mitral valve prosthesis to a native mitral valve of a heart includes positioning a catheter at the native mitral valve, advancing an arm and a first end of a valve frame out of the catheter to a left ventricle of the heart, advancing an anchoring device out of the catheter into the left ventricle around leaflets and chordae tendineae of the native mitral valve, wherein the anchoring device is guided by at least a portion of the arm during the advancing of the anchoring device, and advancing remaining portions of the valve frame out of the catheter, wherein the valve frame is expanded and held in an inner space defined by a coil of the anchoring device.

BRIEF DESCRIPTION OF THE DRAWINGS

0011Further features and advantages will become apparent from the description of embodiments using the accompanying drawings. In the drawings: <ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">Figs. 1A-1B</figref> show close-up perspective views of an end of a delivery catheter from which a prosthetic valve and a helical anchoring device are being delivered.</li><li><figref idref="f0002 f0003 f0004 f0005 f0006 f0007">Figs. 2A-2F</figref> are partial cross-sectional schematic views illustrating a process of employing a delivery system to implant the helical anchoring device and the prosthetic mitral valve in the mitral position of a heart.</li><li><figref idref="f0008">Figs. 3A-3B</figref> show close-up perspective views of the end of the delivery catheter from which a prosthetic mitral valve with a modified arm is being delivered.</li><li><figref idref="f0009">Figs. 4A-4B</figref> show close-up perspective views of the end of a valve delivery catheter and an adjacent helical anchor delivery catheter from which a prosthetic mitral valve and a helical anchoring device are respectively delivered.</li><li><figref idref="f0009">Fig 4C</figref> shows a close-up perspective view of the helical anchoring device and the prosthetic valve of <figref idref="f0009">Figures 4A-4B</figref> after delivery from the adjacent helical anchor delivery catheter and the valve delivery catheter, respectively.</li></ul>

DETAILED DESCRIPTION

0012Disclosed herein are prosthetic mitral heart valves and anchors for use with such valves that allow for a simplified and improved implantation. In various embodiments, a helical anchoring device is formed as a coiled or twisted anchor that includes one or more turns that twist or curve around a central axis. The prosthetic mitral valve is expanded and held within the coil. The anchor and the valve can be delivered in a single procedure. By combining anchor placement with valve implantation, the patient benefits from a faster and simpler prosthetic valve implantation process.

0013<figref idref="f0001">Figures 1A-1B</figref> show close-up perspective views of an end of a delivery catheter 10 from which a prosthetic valve 4 and a helical anchoring device 5 are being delivered. For clarity, structures of the heart have been omitted in these figures.

0014<figref idref="f0001">Figure 1A</figref> shows the prosthetic valve 4 with a portion extending from the delivery catheter 10, and a portion that is still being held in the delivery catheter 10. The prosthetic valve 4 includes a valve frame 48 that is expandable from a collapsed position or configuration in which a diameter of the valve frame 48 is reduced to an expanded position or configuration in which the diameter of the valve frame 48 is increased. The valve frame 48 can be collapsed to facilitate delivery through the delivery catheter 10, and can be expanded during or after placement at a native mitral valve, in order to engage the mitral valve annulus or an anchoring device 5 placed at the mitral position, as will be discussed in greater detail below. The valve frame 48 further houses a plurality of leaflets 41 (e.g., as shown in <figref idref="f0007">Fig. 2F</figref>) for regulating or controlling blood flow through the prosthetic valve 4.

0015The prosthetic valve further includes a plurality of arms 43 that are attached to the valve and extend from the valve frame 48. The arms 43 can be attached to a distal end of the valve frame 48, so that the arms 43 begin exiting the catheter 10 prior to the valve frame 48 during delivery of the prosthetic valve 4. Alternatively, the arms 43 can be attached higher up towards a center the valve frame 48, away from the distal end (e.g., as seen in <figref idref="f0007">Fig. 2F</figref>). The arms 43 are curved, with a first portion that extends distally away from the end of the valve frame 48, and a second portion that curves back up towards the valve frame 48 and extends radially outwardly of the valve frame 48. The second portion of the arms 43 will generally extend radially outwardly farther than the valve frame 48 even after the valve frame 48 has been expanded. The arms 43 are shaped in this manner to facilitate positioning around the native mitral valve leaflets.

0016At least one of the arms 43 is arranged differently (e.g., having a different shape) than the other arms 43. <figref idref="f0001">Figure 1A</figref> shows a loop 42 at a distal end of the leftmost illustrated arm 43. The loop 42 is formed by further bending the end of the arm to define a circular opening. A size of the opening defined by the loop 42 is such that the helical anchoring device 5 can pass through and be guided through the loop 42. The loop 42 may also be slightly larger, in order to also hold and/or guide a helical anchor delivery catheter 11 through which the helical anchoring device 5 is deployed. The loop 42 allows the helical anchor delivery catheter 11 to swivel and to be adjusted into a desired delivery position.

0017The helical anchor delivery catheter 11 is used to deploy and position the helical anchoring device 5. The helical anchor delivery catheter 11 can initially be threaded through or held in the loop 42 of the prosthetic valve 4 during delivery of the prosthetic valve 4 through the catheter 10. In this manner, the deployment of the arms 43 will naturally also bend and/or otherwise position the helical anchor delivery catheter 11 into or close to the desired position for delivery of the helical anchoring device 5. The helical anchor delivery catheter can alternatively be guided to and through the loop 42 after the respective parts have been delivered from the catheter 10. As shown in <figref idref="f0001">Figures 1A and 1B</figref>, the helical anchor delivery catheter 11 is positioned in and passes through the prosthetic valve 4 in the catheter 10. However, the helical anchor delivery catheter 11 can instead be positioned beside the prosthetic valve 4 (<i>i.e.,</i> parallel to prosthetic valve 4) in the catheter 10, or for example can be positioned entirely outside of the catheter 10, as shown in and as will be later discussed with respect to <figref idref="f0009">Figures 4A-4B</figref>.

0018The helical anchor delivery catheter 11 can have a preformed shape that facilitates the positioning of the helical anchor delivery catheter 11 once delivered from the delivery catheter 10. Further, the helical anchor delivery catheter 11 can be steerable through one of various means.

0019<figref idref="f0001">Figures 1A and 1B</figref> show an initial process of the helical anchoring device 5 being pushed out or otherwise delivered from the helical anchor delivery catheter 11. As will be discussed in greater detail below, the helical anchoring device 5 is formed as a coiled or twisted anchor that includes one or more turns that twist or curve around a central axis. The helical anchoring device 5 defines a generally circular or cylindrical inner space in which the valve frame 48 of the prosthetic valve 4 can expand and be held. The helical anchoring device 5 can be preformed to have the coiled or twisted shape, and is made of or includes a material that allows the helical anchoring device 5 to be deformed (e.g., straightened) when it is held in the helical anchor delivery catheter 11, and where the anchoring device 5 reverts back to its coiled shape when the anchoring device 5 is delivered from the helical anchor delivery catheter 11. The size and/or radius of curvature of the helical anchoring device 5, and the positioning of the helical anchoring delivery catheter 11, is such that the anchoring device 5 can be guided entirely around the native mitral valve leaflets and chordae tendineae when the anchoring device 5 is being deployed. <figref idref="f0001">Fig. 1A</figref> shows the beginning stages of deployment of the anchoring device 5, where only a distal tip of the anchoring device 5 extends from the helical anchoring delivery catheter 11, while <figref idref="f0001">Fig. 1B</figref> shows the anchoring device 5 being deployed almost one complete revolution around the valve frame 48 of the prosthetic valve 4. Implantation of the both the prosthetic valve 4 and the anchoring device 5 with respect to the various features of the heart will be discussed in greater detail with respect to <figref idref="f0002 f0003 f0004 f0005 f0006 f0007">figures 2A-2F</figref> below.

0020<figref idref="f0002 f0003 f0004 f0005 f0006 f0007">Figures 2A-2F</figref> show a delivery system 100 and, for illustrative purposes, a method for positioning the prosthetic mitral valve 4 and the helical anchoring device 5 at the native mitral valve 3 of a patient's heart 2.

0021<figref idref="f0002">Figure 2A</figref> shows the delivery system 100 including a catheter 1 which has been advanced in the heart 2 through a peripheral vein, for example, the inferior vena cava 21, into the right atrium 22, across the atrial septum 23 to the left atrium 24 and through the native mitral valve 3 such that the end of the catheter 1 sits in the left ventricle 25 near the native mitral valve 3. The catheter 1 can be introduced into a patient's venous system by percutaneous puncture or by a small surgical cut down at the patient's groin, as is commonly known. Alternatively, the catheter 1 can be introduced anywhere in the lower abdomen or retroperitoneal region, or in the neck or shoulder regions through the subclavian or axillary veins or the jugular system in the neck. Further, the catheter 1 can be introduced through the superior vena cava 26 or can enter the heart 2 directly through an outer wall of the left atrium 24. As shown in <figref idref="f0002">Fig. 2A</figref>, the delivery catheter 10 extends from the catheter 1 and is positioned in the left ventricle 25.

0022The catheter 10 contains or holds the prosthetic mitral valve 4 that can be implanted in the region of the patient's native mitral valve 3, as shown in <figref idref="f0006 f0007">Figs. 2E-2F</figref>. The prosthetic valve 4 is expandable as previously discussed, and can be self expanding. Nitinol is typically used to create the valve frame 48 of the self-expanding prosthetic valve 4, but other shape memory materials can be used as well. The valve frame houses artificial leaflets 41, as shown in <figref idref="f0007">Fig. 2F</figref>, which are typically made from cow or pig pericardium. The leaflets 41 can also be synthetic or derived from other sources such as human cadavers or by biologic tissue engineering. One biologic material which has favorable properties is tissue derived from small intestinal mucosa.

0023<figref idref="f0003">Figure 2B</figref> shows a close up view of the catheter 1 located inside the left heart 27 with the tip 12 of the delivery catheter 10 just below the native leaflets 31 of the mitral valve 3. A portion of the prosthetic valve 4 has been delivered (<i>e.g.,</i> deployed outwardly) from the delivery catheter 10 within the left ventricle 25 such that the loop 42 protrudes from the tip 12 of the delivery catheter 10.

0024<figref idref="f0004">Figure 2C</figref> shows the further delivery of the prosthetic mitral valve 4 from the delivery catheter 10. The arms 43 extend from or near the end of the valve frame 48 of the prosthetic valve 4 that sits in the left ventricle 25, and wrap around the native leaflets 31 and serve to anchor the prosthetic valve 4 firmly against the margins of the native mitral leaflets 31. The arrows illustrate the direction in which the arms 43 wrap around the lower margin of the native mitral leaflets 31 after the arms 43 have been outwardly deployed from the delivery catheter 10. The arms 43 will help prevent the prosthetic valve 4 from dislodging upward into the left atrium 24 when the prosthetic valve 4 is fully positioned.

0025A number of arms 43 are useful to provide a lower plane of attachment of the prosthetic mitral valve 4 to the native mitral valve 3. The arms 43 can vary in length and in character and construction. It will be understood that more or less than two arms 43 can be used, even though only two arms are shown in <figref idref="f0002 f0003 f0004 f0005 f0006 f0007">Figures 2A-2F</figref> for the purposes of illustration.

0026One of the arms 43 has the loop 42 at its far or distal end to direct or control a helical anchor delivery catheter 11 that contains the helical anchoring device 5. The helical anchor delivery catheter 11 has been preloaded into the loop 42. The arm 43 including the loop 42 can be of heavier construction than the other arms 43 and does not have to resemble the other arm or arms 43 that do not include a loop 42.

0027The arms 43 have shape memory properties or are otherwise resilient, such that when they are deployed outwardly from the delivery catheter 10 they can revert back to their curved shapes and wrap around the native mitral leaflets 31.

0028The arm 43 with the loop 42 wraps around the native mitral leaflet 31 and the attached helical anchor delivery catheter 11 is carried with it so that the chordae tendineae 32 and the patient's mitral valve leaflets 31 sit inside (<i>i.e.,</i> on a concave side of the curvature of) an exposed end of the helical anchoring device 5. When the helical anchoring device 5 is advanced from this location, it will encircle the chordae tendineae 32 so that the native mitral valve leaflets 31 and the chordae 32 will be trapped inside a circle created by the helical anchoring device 5, as will be seen later.

0029The loop 42 at the end of the arm 43 swings the helical anchor delivery catheter 11 around the leaflets 31 and above the chordae 32 into a preferred position under the native mitral valve annulus 34. This particular arm 43 can have a double function of attaching the prosthetic valve 4 to the leaflet margin and guiding delivery of the helical anchoring device 5. The loop 42 can be sufficiently large to allow the helical anchor delivery catheter 11 to pivot or swivel as the system is deployed.

0030The helical anchoring device 5 is preferably delivered in a plane close to parallel to the underside of the native mitral valve 3. The helical anchor delivery catheter 11 is also aimed or directed to this plane by the loop 42. The loop 42 can include a short tube that forces the helical anchor delivery catheter 11 into a favorable plane and orientation. Or the helical anchor delivery catheter 11 can be steerable. Many steerable catheters are known and available in the field of art.

0031Further, devices other than the loop 42 can direct the delivery of the helical anchoring device 5. For example, a cell of a stent frame that composes part of the prosthetic mitral valve 4 can also perform the same function as the loop 42 shown here. A hook or a tube can also be used. Any structure that can direct the helical anchoring device 5 around the native leaflets 31 can be added to the prosthetic valve 4. The structure can be permanently fabricated in the prosthetic valve 4 or can be temporary. For example, a loop of suture could be used to create the loop 42. The suture could then be withdrawn. Alternatively, prior mitral valve prosthetics having arms or wings can be modified or retrofitted with the loop 42 of the present prosthetic valve 4 in order to facilitate delivery of the helical anchoring device 5.

0032The arms 43 in <figref idref="f0004 f0005 f0006 f0007">Figures 2C-2F</figref> can be quite slender. In practice, the arms 43 can be composed of pairs or triplets of wires that are fused at the ends 45 of the arms 43. These narrow terminal ends 45 to the arms 43 facilitate the arms 43 passing between the chordae tendineae 32 at their margin with the free edges 33 of the mitral leaflets 31 to allow the arms 43 to wrap around the leaflets 31. The chordae 32 are closely packed around some areas of the native mitral valve 3, and slender arms 43 will better facilitate passing of the arms 43 between the chordae tendineae 32. Once the slender part of the arms 43 pass, thicker parts of the arms 43 can move between the chordae 32 by spreading them apart. Thus, the arm 43 can be slender (or composed of a single wire or a fusion of wires) at the tip 45 and is more robust closer to the main body of the prosthetic valve 4 (for more powerful attachment). Further, the arms 43 can also be shorter or longer than illustrated in <figref idref="f0004 f0005 f0006 f0007">Figures 2C-2F</figref>.

0033Deployment of the helical anchoring device 5 can be started anywhere around the mitral valve annulus 34. For example, deployment of the helical anchoring device 5 can start in or adjacent to the middle of a leaflet 31. This would be an advantage for an operator who, for example, would not have to precisely locate a commissure of the native mitral valve to begin the anchoring device delivery procedure, thereby simplifying the procedure.

0034<figref idref="f0005">Figure 2D</figref> shows a close-up schematic view of the helical anchoring device 5 being delivered under the native mitral valve leaflets 31 at the mitral position. The arrow illustrates the direction in which the helical anchoring device 5 is deployed from the delivery catheter 11 under the native mitral valve 3. Any number of turns can be delivered depending on the particular helical anchoring device 5 used. An inner diameter of the helical anchoring device 5 can preferentially be slightly less than an outer diameter of the fully expanded mitral prosthetic valve 4 in order to promote engagement between the helical anchoring device 5 and the prosthetic valve 4.

0035The partially delivered prosthetic valve 4 can serve to center the delivery of the helical anchoring device 5. It can also provide a stable platform for delivery of the helical anchoring device 5.

0036As illustrated in <figref idref="f0006">Figure 2E</figref>, three turns of the helical anchoring device 5 have been placed below the native mitral valve 3. The native mitral valve leaflets 31 are positioned between the helical anchoring device 5 and the prosthetic mitral valve 4, which is shown in <figref idref="f0006">Figure 2E</figref> as being about to expand. Once the prosthetic valve 4 is expanded, the helical anchoring device 5 aids in securely positioning the prosthetic valve 4 and prevents leaks around the prosthetic valve 4 by sealing the native leaflets 31 to or against the prosthetic valve 4. Opposing forces between the helical anchoring device 5 and the prosthetic valve 4 help position and stabilize the prosthetic valve 4.

0037In <figref idref="f0006">Figure 2E</figref>, the delivery catheter 10 has been omitted for simplicity. In practice, the prosthetic valve 4 would spring open in <figref idref="f0006">Figure 2E</figref> when the delivery catheter 10 has been removed (the arrows indicate the direction in which the prosthetic valve 4 would normally spring open). However, in <figref idref="f0006">Figure 2E</figref> the prosthetic valve 4 is still in a closed position in order to allow clear visualization of the turns of the helical anchoring device 5 under the native mitral valve 3. The prosthetic valve 4 further includes an expandable atrial portion 46 that extends or projects from or near a second end of the valve frame 48 opposite the end from which the arms 43 extend. The atrial portion 46 is configured to be held against or to abut against a wall of the left atrium 24, to help further stabilize the prosthetic valve 4 at the mitral position. The atrial portion 46 of the prosthetic valve 4 can expand to a size greater than the mitral valve annulus 34, for example, to restrict movement of the prosthetic valve 4 into the left ventricle 25.

0038In <figref idref="f0006">Figure 2E</figref>, there are three turns of the helical anchoring device 5, but any number of turns can be used. The turns sit up against the underside of the mitral valve annulus 34 and the leaflets 31 in order to provide a solid buttress to fix the helical anchoring device 5 in position and to prevent movement of the prosthetic valve 4 into the left atrium 24 when the left ventricle 25 contracts. Since the arms 43 are wrapped around the helical anchoring device 5, the entire structure is stabilized in position.

0039The use of a helical anchoring device that can optionally be delivered at the same time as a prosthetic valve provides the interventionalist a considerable amount of choice. For example, the prosthetic valve 4 can be able to be re-sheathed, <i>i.e.,</i> re-inserted into the delivery catheter 10, allowing the prosthetic valve 4 to be partly advanced and tested for its fit during a procedure. If the operator is not happy with the positioning before the final release of the prosthetic valve 4, the prosthetic valve 4 can be pulled back into the delivery catheter 10.

0040In some illustrative methods of use, the prosthetic valve 4 can be positioned first without the helical anchoring device 5 in place. If the anchoring of the prosthetic valve 4 appears to be strong and stable and there is no evidence of movement or leak, the prosthetic valve 4 can be released without the helical anchoring device 5. On the other hand, if the operator is not satisfied with, for example, the position or stability of the prosthetic valve 4 in the mitral position without the helical anchoring device 5, the prosthetic valve 4 can be pulled back into the delivery catheter 10. Then, the helical anchoring device 5 can be placed first and the prosthetic valve 4 can be positioned and expanded therein. This would let the user decide the clinical need for the extra anchoring of the helical anchoring device 5 based on each individual procedure.

0041In <figref idref="f0007">Figure 2F</figref>, the fully implanted prosthetic valve 4 is shown in the mitral position. The arms 43 have wrapped around the native mitral valve leaflets 31 to prevent the prosthetic valve 4 from moving upward into the left atrium 24. The native mitral leaflets 31 are compressed tightly under the arms 43 and a solid mechanical structure has been created to prevent the prosthetic valve 4 from migrating.

0042The turns of the helical anchoring device 5 also compress against the body of the prosthetic valve 4 to position, orient and prevent movement of the prosthetic valve 4. The helical anchoring device 5 provides a frictional attachment of the body of the prosthetic valve 4 to the native mitral valve leaflets 31 and serves to anchor the arms 43 that wrap around the helical anchoring device 5.

0043The upper atrial portion 46 of the prosthetic mitral valve 4 is shown with a wide area that sits inside the left atrium 24 to promote attachment to or abutment against the wall of the left atrium 24. However the force or pressure that tends to urge the prosthetic mitral valve 4 from the left atrium 24 into the left ventricle 25 is low, and so the atrial portion 46 may not be necessary and could be eliminated or reduced in a clinical prosthesis.

0044The turns of the helical anchoring device 5 aid in overcoming variations in the lengths of the patient's leaflets 31, variations in the length of the chordae tendineae 32 and variations in the attachment point of the chordae 32 in the left ventricle 25. When a prosthetic mitral valve with arms 43 wrapping around the leaflets 31 is used without any helix or anchor encircling under the leaflets 31, the depth or robustness of fixation of the prosthetic mitral valve can vary around the perimeter of the implanted prosthetic mitral valve. For example, if the chordae tendineae 32 attached to the middle part of the posterior leaflet 31 were very elongated or ruptured (a common situation), the arms 43 can fail to wrap around and engage the leaflet 31 at this location. Or there can be a very limited engagement between one of the arms 43 and the leaflet 31, causing the arm 43 to move to or come to rest at a much higher plane closer to the valve annulus 34. If any of these occurs, the part of the prosthetic valve where this happens would sit higher or closer to the native mitral valve 3, which may create a skew in the prosthetic valve so the prosthetic valve would sit at an angle to the plane of inflow of the valve. As the heart beats, there is a large load on the prosthetic valve and it can begin to rock and shift. The heart beats almost 100,000 times per day and after several days or weeks or months, the prosthetic valve may shift, move and dislodge. Also, if the leaflets 31 or chordae 32 were very elongated, there may be no contact with the arms, and an effective seal around the implant may not be formed. This could result in a large paravalvular leak due to lack of engagement of the prosthetic valve with the native mitral leaflets 31. The helical anchoring device 5 under the leaflets 31 can compress leaflet tissue against the prosthetic valve and prevent this problem. The helical anchoring device 5 can sit in one plane and prevent problems related to variations in patient anatomy.

0045In clinical practice, there are virtually limitless variations in the size of the leaflets 31, the character of the leaflets 31, the chordal lengths and the attachment of chordae 32 as well as the diameter of the mitral annulus 34. The use of the helical anchoring device 5 under the leaflets 31 neutralizes many of these variables since the fixation point of the arms 43 can be brought to the lowest turn of the helical anchoring device 5. This position can be determined in advance by selecting the number of turns of the helical anchoring device 5 and the thickness of the helical anchoring device 5 to match the turning point of the arms 43 at the lowest part of the prosthetic valve 4.

0046Thus, the helical anchoring device 5 can create a common and predefined plane for the anchoring of the arms 43 of the prosthetic mitral valve 4. In the situation described previously where some of the chordae 32 are stretched and where contact between the prosthetic valve 4 may otherwise be loose or less secure without the helical anchoring device 5, the attachment of the prosthetic mitral valve 4 in this region can be to the helical anchoring device 5 instead. This would create a common plane for the lowest point of the prosthetic mitral valve 4.

0047Therefore, more turns of the helical anchoring device 5 can be added to ensure the arms 43 of the prosthetic valve 4 are at a common lowest plane throughout its perimeter. The helical anchoring device 5 can be made thicker. Further, waves or undulations can be added to the turns of the helical anchoring device 5 to expand the height of the helical anchoring device 5.

0048The helical anchoring device 5 thus improves stability of the prosthetic valve 4 by providing an anchor point for the arms 43 of the prosthetic valve 4 to wrap around and at the same time the helical anchoring device 5 can trap the perimeter of the barrel of the prosthetic valve 4 along its length. The combination of these features provides great stability to the prosthetic valve 4. It also seals the native mitral valve 3 against the prosthetic valve 4 to prevent a paravalvular leak.

0049In addition, patients' native mitral valves (i.e., leaflets 31, annulus 34, and chordae 32) come in all varieties and combinations. It is less practical for a manufacturer to make different lengths and depths of anchoring arms 31 and for the operator to deliver these products perfectly into position inside the patient. It can be more practical to adjust for these variations by placing the helical anchoring device 5 below the prosthetic valve 4 and using this helical anchoring device 5 to create a lowest plane for the arms 43 to anchor against.

0050<figref idref="f0008">Figures 3A-3B</figref> show the end of the delivery catheter 10 from which a prosthetic valve 4' is being delivered. For clarity, structures of the heart 2 have been omitted in these figures.

0051As described above, the helical anchor delivery catheter 11 that delivers the helical anchoring device 5 under the native mitral leaflets 31 is separate from the prosthetic device 4. As illustrated in <figref idref="f0008">Figures 3A-3B</figref>, the helical anchor delivery catheter has been incorporated into the prosthetic valve 4' as a modified arm 43'. The prosthetic valve 4' includes the modified arm 43' that wraps around one of the mitral leaflets 31, similar to the other arms 43. Here, the modified arm 43' is a hollow tube that can be loaded with the helical anchoring device 5, and which is sized so that the helical anchoring device can be advanced therethrough. The modified arm 43' includes a bend 47 and a portion at a distal end that is angled relative to the rest of the arm 43', so that a distal portion of the arm 43' extends circumferentially around the prosthetic valve 4'. An opening of the hollow tube therefore points circumferentially around the prosthetic valve 4' to help direct the helical anchoring device 5 around the native mitral leaflets 31 and the chordae 32. However, any structure on the modified arm 43' of the prosthetic valve 4' or any part of the prosthetic valve 4' that could guide the helical anchoring device 5 can suffice to direct the helical anchoring device 5 into the correct position. When the modified arm 43' wraps around one of the mitral leaflets 31, the helical anchoring device 5 is carried into the correct location and to the correct plane for delivery. The modified arm 43' can be preformed and made of a shape-memory material, such as nitinol.

0052<figref idref="f0008">Figure 3B</figref> shows almost one complete turn of the helical anchoring device 5 extending from the tubular arm 43'. As described above, the helical anchoring device 5 can complete multiple turns under or around the native mitral leaflets 31. As shown, the prosthetic mitral valve can be modified to carry the helical anchoring device 5 without the need for a separate helical anchor delivery catheter positioned under or around the native mitral leaflets 31.

0053<figref idref="f0009">Figures 4A-4B</figref> show close-up perspective views of the end of the delivery catheter 10 and an adjacent helical anchor delivery catheter 11".

0054In <figref idref="f0001">Figs. 1A-1B</figref>, the helical anchor delivery catheter 11 is positioned inside the prosthetic mitral valve 4 in the catheter 10. However, the helical anchor delivery catheter 11" and the prosthetic valve 4" are delivered side by side. As shown in <figref idref="f0009">Figures 4A-4B</figref>, the prosthetic valve 4 can be constructed similarly to the prosthetic valve 4 of <figref idref="f0001">Figs. 1A-1B</figref>. The helical anchor delivery catheter 11" is instead positioned outside the delivery catheter 10 that delivers the prosthetic mitral valve 4". The helical anchor delivery catheter 11" passes through the loop 42 in one of the arms 43 in the prosthetic mitral valve 4". The arrows adjacent the helical anchoring device 5 demonstrate the direction in which the helical anchoring device 5 is being delivered from the end of the helical delivery catheter 11".

0055<figref idref="f0009">Figure 4B</figref> shows the helical anchoring device 5 further extended from the helical anchor delivery catheter 11". The end of the helical anchor delivery catheter 11" is still in the loop 42 at the end one of the arms 43, and almost one full turn of the helical anchoring device 5 has been delivered.

0056<figref idref="f0009">Figure 4C</figref> shows a close-up perspective view of the helical anchoring device 5 and the prosthetic valve 4" of <figref idref="f0009">Figures 4A-4B</figref> after delivery from the helical anchor delivery catheter 11" and the delivery catheter 10, respectively.

0057In <figref idref="f0009">Figure 4C</figref>, about three turns of the helical anchoring device 5 have been delivered under the schematically illustrated plane 35 of the native mitral valve 3. However, any number of turns of the helical anchoring device 5 can be provided in order to provide support to the prosthetic valve 4". The helical anchor delivery catheter 11" has been removed in <figref idref="f0009">Figure 4C</figref> for simplicity. The delivery catheter 10 delivering the prosthetic valve 4" has also been removed. As discussed regarding <figref idref="f0006">Figure 2E</figref> above, the body of the prosthetic valve 4" would generally spring open when the delivery catheter 10 is removed. But for the purpose of illustration, the prosthetic valve 4" is shown in <figref idref="f0009">Figure 4C</figref> in its closed position to make visualization of the helical anchoring device 5 and the prosthetic valve 4" clearer.

0058Various other modifications or alternative configurations can be made to the prosthetic valves, helical anchors, and/or deployment systems according to the above described disclosure. For example, any variation of the valve prosthesis where controlled deployment of a helical anchor can be facilitated by a portion of the prosthesis that interacts with either the helical anchor itself or with a catheter for delivering the helical anchor may be alternatively arranged. The interacting feature is embodied in an arm of the valve prosthesis as described above . With respect to the helical anchor, the number of coils can be further varied, based on for example, properties of the native mitral valve and/or desired positioning of the valve prosthesis. Various other coil shapes, lengths, and arrangements and modifications can also be made based on a wide range of considerations.

0059For purposes of this description, certain aspects, advantages, and novel features of the embodiments of this disclosure are described herein. The disclosed methods, apparatus, and systems should not be construed as being 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, apparatus, 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.

0060Although the operations 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 set forth below. 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. Additionally, the description sometimes uses terms like "provide" or "achieve" to describe the disclosed methods. These terms are high-level abstractions of the actual operations that are performed. The actual operations that correspond to these terms may vary depending on the particular implementation and are readily discernible by one of ordinary skill in the art.

0061In view of the many possible embodiments to which the principles of the disclosure may be applied, it should be recognized that the illustrated embodiments are only preferred examples and should not be taken as limiting the scope of the disclosure. Rather, the scope of the disclosure is defined by the following claims.