US20100121437A1 - Transvalvular intraannular band and chordae cutting for ischemic and dilated cardiomyopathy - Google Patents

Abstract

Mitral valve prolapse and mitral regurgitation can be treating by implanting in the mitral annulus a transvalvular intraannular band. The band is positioned so that it extends transversely across a coaptive edge formed by the closure of the mitral valve leaflets, to inhibit prolapse into the left atrium. At least one marginal chordae is severed, to permit leaflet closure against the band.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application is a continuation-in-part of U.S. patent application Ser. No. 12/104,011 filed Apr. 16, 2008, the disclosure of which is incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
• 1. Field of the Invention
• Embodiments of the present invention relate generally to treatment of mitral or tricuspid valve prolapse and mitral regurgitation, and more specifically, relate to the use of a transvalvular band to treat mitral valve prolapse and mitral regurgitation.
• 2. Description of the Related Art
• The heart is a double (left and right side), self-adjusting muscular pump, the parts of which work in unison to propel blood to all parts of the body. The right side of the heart receives poorly oxygenated (“venous”) blood from the body from the superior vena cava and inferior vena cava and pumps it through the pulmonary artery to the lungs for oxygenation. The left side receives well-oxygenated (“arterial”) blood from the lungs through the pulmonary veins and pumps it into the aorta for distribution to the body.
• The heart has four chambers, two on each side—the right and left atria, and the right and left ventricles. The atria are the blood-receiving chambers, which pump blood into the ventricles. A wall composed of membranous and muscular parts, called the interatrial septum, separates the right and left atria. The ventricles are the blood-discharging chambers. A wall composed of membranous and muscular parts, called the interventricular septum, separates the right and left ventricles.
• The synchronous pumping actions of the left and right sides of the heart constitute the cardiac cycle. The cycle begins with a period of ventricular relaxation, called ventricular diastole. The cycle ends with a period of ventricular contraction, called ventricular systole.
• The heart has four valves that ensure that blood does not flow in the wrong direction during the cardiac cycle; that is, to ensure that the blood does not back flow from the ventricles into the corresponding atria, or back flow from the arteries into the corresponding ventricles. The valve between the left atrium and the left ventricle is the mitral valve. The valve between the right atrium and the right ventricle is the tricuspid valve. The pulmonary valve is at the opening of the pulmonary artery. The aortic valve is at the opening of the aorta.
• Various disease processes can impair the proper functioning of one or more of these valves. These include degenerative processes (e.g., Barlow's Disease, fibroelastic deficiency), inflammatory processes (e.g., Rheumatic Heart Disease) and infectious processes (e.g., endocarditis). In addition, damage to the ventricle from prior heart attacks (i.e.; myocardial infarction secondary to coronary artery disease) or other heart diseases (e.g., cardiomyopathy) can distort the valve's geometry causing it to dysfunction.
• The mitral valve is comprised of an anterior leaflet and a posterior leaflet. The bases of the leaflets are fixed to a circumferential partly fibrous structure, the annulus, preventing dehiscence of the valve. A subvalvular apparatus of chordae and papillary muscles prevents the valve from prolapsing into the left atrium. Mitral valve disease can be expressed as a complex variety of pathological lesions of either valve or subvalvular structures, but can also be related to the functional status of the valve. Functionally the mitral valve disease can be categorized into two anomalies, increased leaflet motion i.e. leaflet prolapse leading to regurgitation, or diminished leaflet motion i.e. restricted leaflet motion leading to obstruction and/or regurgitation of blood flow.
• Leaflet prolapse is defined as when a portion of the leaflet overrides the plane of the orifice during ventricular contraction. The mitral regurgitation can also develop secondary to alteration in the annular ventricular apparatus and altered ventricular geometry, followed by incomplete leaflet coaptation. In ischemic heart failure this can be attributed to papillary or lateral wall muscle dysfunction, and in non-ischemic heart failure it can be ascribed to annular dilation and chordal tethering, all as a result of dysfunctional remodeling.
• The predominant cause of dysfunction of the mitral valve is regurgitation which produces an ineffective cardiac pump function resulting in several deleterious conditions such as ventricular and atrial enlargement, pulmonary hypertension and heart-failure and ultimately death.
• The main objective for the surgical correction is to restore normal function and not necessarily anatomical correction. This is accomplished by replacing the valve or by reconstructing the valve. Both of the procedures require the use of cardiopulmonary bypass and is a major surgical operation carrying a non-negligible early morbidity and mortality risk, and a postoperative rehabilitation for months with substantial postoperative pain. Historically, the surgical approach to patients with functional mitral regurgitation was mitral valve replacement, however with certain adverse consequences such as thromboembolic complications, the need for anticoagulation, insufficient durability of the valve, loss of ventricular function and geometry.
• Reconstruction of the mitral valve is therefore the preferred treatment for the correction of mitral valve regurgitation and typically consists of a quadrangular resection of the posterior valve (valvuloplasty) in combination with a reduction of the mitral valve annulus (annuloplasty) by the means of suturing a ring onto the annulus. These procedures are surgically demanding and require a bloodless and well-exposed operating field for an optimal surgical result. The technique has virtually not been changed for more than three decades.
• More recently, prolapse of the valve has been repaired by anchoring the free edge of the prolapsing leaflet to the corresponding free edge of the opposing leaflet and thereby restoring apposition but not necessarily coaptation. In this procedure a ring annuloplasty is also required to attain complete coaptation.
• This method commonly referred to as an edge-to-edge or “Alfieri” repair also has certain drawbacks such as the creation of a double orifice valve and thereby reducing the effective orifice area. Several less invasive approaches related to the edge-to-edge technique has been suggested, for repairing mitral valve regurgitation by placing a clip through a catheter to suture the valve edges. However, it still remains to conduct an annuloplasty procedure, which has not yet been resolved by a catheter technique and therefore is to be performed by conventional surgery, which makes the method impractical.
• Notwithstanding the presence of a variety of presently available surgical techniques and promising catheter based procedures for the future, there remains a need for a simple but effective device and corresponding surgical, minimally invasive or transvascular procedure to reduce mitral valve regurgitation.
SUMMARY OF THE INVENTION
• There is provided in accordance with one aspect of the present invention, a method of treating ischemic or dilated cardiomyopathy. The method comprises the steps of providing an intraannular transvalvular band, dimensioned for attachment within the plane of the mitral valve annulus. The band is attached within the plane of the annulus, such that a portion of the band extends into the ventricular side of the plane, to support the leaflets and elevate the position of the coaptive edges in the direction of the ventricle during valve closure. At least one marginal chordae is manipulated, to permit leaflet coaption.
• Depending upon the desired clinical outcome, at least two or three or four or more marginal chordae are manipulated to permit leaflet coaption. Manipulation of the marginal chordae may comprise severing the chordae, such as by a mechanical cutting instrument, or any of a variety of tissue severing energy modalities including radio frequency, microwave, ultrasound, laser, cryoablation or other cutting modality known in the art.
• Further features and advantages of the present invention will become apparent to those of skill in the art in view of the detailed description of preferred embodiments which follows, when considered together with the attached drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a simplified cross-sectional view of the heart with a normal mitral valve during systole. The intraannular plane is illustrated relative to supraannular and infrannular.
• FIG. 2 is a cross-sectional view of the heart with a normal mitral valve during diastole. The axis of the mitral valve is illustrated, and shown piercing the intraannular plane.
• FIG. 3 is a bottom view of the normal mitral valve ofFIG. 1 during systole looking from the left atrium to the left ventricle.
• FIG. 4 is a bottom view of the normal mitral valve ofFIG. 2 during diastole looking from the left atrium to the left ventricle.
• FIG. 5 is a cross-sectional schematic view of the normal mitral valve ofFIG. 1 during systole, illustrating the depth of the coaption zone.
• FIG. 6 is a cross-sectional schematic view of the normal mitral valve ofFIG. 2 during diastole.
• FIG. 7 is a cross-sectional view of the heart during systole showing a mitral valve with a prolapsed anterior leaflet caused by the rupture of the chordae tendineae attached to the anterior leaflet.
• FIG. 8 is a bottom view of the mitral valve ofFIG. 7 having a prolapsed anterior leaflet looking from the left atrium to the left ventricle.
• FIG. 9 is a cross-sectional view of the heart during systole showing a mitral valve with a prolapsed posterior leaflet caused by the rupture of the chordae tendineae attached to the posterior leaflet.
• FIG. 10 is a bottom view of the mitral valve ofFIG. 9 having a prolapsed posterior leaflet looking from the left atrium to the left ventricle.
• FIG. 11 is a cross-sectional view of the heart during systole showing a mitral valve with anterior leaflet prolapse.
• FIG. 11A is a cross sectional view as inFIG. 11, showing posterior leaflet prolapse.
• FIG. 11B is a cross sectional view as inFIG. 11, showing bileaflet prolapse with mitral regurgitation.
• FIG. 11C illustrates a dilated mitral annulus with little or no coaption of both leaflets causing central mitral regurgitation in ischemic cardiomyopathy.
• FIG. 12 is a top view of an embodiment of a transvalvular band.
• FIG. 13 is a side view of the transvalvular band ofFIG. 12.
• FIG. 14 is a cross-sectional view of a transvalvular band with a triangular cross-section.
• FIG. 15 is a cross-sectional view of a transvalvular band with an oblong cross-section.
• FIG. 16 is a cross-sectional view of a transvalvular band with a circular cross-section.
• FIG. 17 is a cross-sectional view of a transvalvular band with a rectangular cross-section.
• FIG. 18 is a top view of another embodiment of a transvalvular band.
• FIGS. 19A and B show a perspective view of yet another embodiment of a transvalvular band, with a widened coaptive edge support portion.
• FIGS. 20-23 are top views of other embodiments of a transvalvular band.
• FIG. 23A shows a central mitral transvalvular band with posterior annuloplasty ring.
• FIG. 23B shows an intraannular band formed from a length of wire.
• FIGS. 24-27 are side views of other embodiments of a transvalvular band.
• FIG. 28 is a cross-sectional view of a heart during systole with a transvalvular band implanted in the mitral annulus.
• FIG. 29 is a bottom view of the mitral valve ofFIG. 28 during systole with a transvalvular band implanted in the mitral annulus looking from the left atrium to the left ventricle.
• FIG. 30 is a cross-sectional view of a heart during diastole with mitral valve and a transvalvular band implanted in the mitral annulus.
• FIG. 31 is a bottom view of the mitral valve ofFIG. 30 during diastole with a transvalvular band implanted in the mitral annulus looking from the left atrium to the left ventricle.
• FIG. 32 is a cross-sectional schematic view of the mitral valve ofFIG. 28 during systole with a transvalvular band implanted in the mitral annulus.
• FIG. 33 is a cross-sectional schematic view of the mitral valve ofFIG. 32 during systole without the transvalvular band implanted in the mitral annulus.
• FIG. 34 is a cross-sectional schematic view of the mitral valve ofFIG. 30 during diastole with the transvalvular band implanted in the mitral annulus.
• FIG. 35 is a cross-sectional schematic view of the mitral valve ofFIG. 34 during diastole without the transvalvular band implanted in the mitral annulus.
• FIG. 36 is a bottom view of the mitral valve during systole with another embodiment of the transvalvular band implanted in the mitral annulus looking from the left atrium to the left ventricle.
• FIG. 37 is a cross-sectional view of a transvalvular band with a transverse leaflet support.
• FIG. 38 is a cross-sectional schematic view of the mitral valve treated with the transvalvular band ofFIG. 37 and an Alfieri type procedure.
• FIG. 39 is a schematic cross-sectional view of the heart, showing a typical antegrade approach to the mitral valve by way of a transseptal crossing.
• FIG. 40 is a cross sectional view as inFIG. 39, showing placement of a guidewire through the mitral valve.
• FIG. 41 is a cross sectional view of the heart showing a typical retrograde approach to the mitral valve by way of a femoral artery access.
• FIG. 42 shows a retrograde approach as inFIG. 41, with a guidewire placed across the mitral valve.
• FIG. 43A is a schematic view of the distal end of a percutaneous deployment catheter having a self-expandable implant positioned therein.
• FIG. 43B is a schematic view as inFIG. 43A, with the implant partially deployed from the catheter.
• FIG. 43C is a schematic view of the deployment catheter showing the implant fully expanded at the deployment site, but still tethered to the deployment catheter.
• FIG. 43D is a side elevational view of the implant ofFIG. 43C.
• FIG. 43E is an end view taken along theline43E-43E ofFIG. 43D.
• FIG. 44A is a side elevational perspective view of an anchor deployment catheter in accordance with the present invention.
• FIG. 44B is a cross sectional view taken along theline44B-44B ofFIG. 44A.
• FIG. 45A is a schematic plan view of a self-expandable transvalvular band in accordance with the present invention.
• FIG. 45B is a side elevational view of the transvalvular band ofFIG. 45A shown in a reduced crossing profile (folded) configuration, and attached to three control wires.
• FIG. 46A is a cut-away perspective view of the distal end of a deployment catheter having a self-expandable implant contained therein.
• FIG. 46B is a deployment catheter as inFIG. 46A, with the implant partially deployed.
• FIG. 46C is a view as inFIG. 46B, showing the implant released from the deployment catheter, but connected to three control wires.
• FIG. 46D is a view as inFIG. 46C with a tissue anchor deployment catheter.
• FIG. 46E is a cross sectional view of a mitral valve, having an implant anchored in place and the deployment catheter removed.
• FIG. 47A is a side elevational view of the distal end of a deployment catheter, having an implant partially deployed therefrom.
• FIG. 47B is a schematic view of the catheter and implant ofFIG. 47A, during implantation at the mitral valve.
• FIG. 47C is a schematic view as inFIG. 47B, with the tissue anchor deployment guides removed.
• FIG. 47D is a schematic view as inFIG. 47C, with the implant configured to move coaption earlier in the cardiac cycle.
• FIG. 47E is a schematic view of the implant ofFIG. 47D, with the deployment catheter removed.
• FIG. 48A is schematic cross sectional view of a transapical deployment device positioned across the mitral valve.
• FIG. 48B is a schematic view of the device ofFIG. 48A, with tissue anchors engaged at the mitral valve annulus.
• FIG. 48C is a schematic view as inFIG. 48B, with the deployment catheter withdrawn through the mitral valve.
• FIG. 48D is a schematic view as inFIG. 48C, in an embodiment having a transventricular support.
• FIGS. 49A through 49G illustrate an implantation sequence for a transvalvular band at the mitral valve, via a transapical access.
• FIG. 49H shows an alternate end point, in which the transvalvular band is additionally provided with a transventricular truss and an epicardial anchor.
• FIG. 50A is a side elevational schematic view of the distal end of a deployment catheter, having a rolled up transvalvular band therein.
• FIG. 50B is an illustration as inFIG. 50A, following distal deployment of the transvalvular band.
• FIGS. 51A and 51B illustrate top plan views and side views of a transvalvular band in accordance with the present invention.
• FIG. 51C illustrates a perspective view of one embodiment of a transvalvular band in a rolled-up configuration and mounted on a delivery mandrel.
• FIG. 51D illustrates a view of at least a non-linear portion of a strut ofFIG. 51B.
• FIGS. 52A through 52C illustrate a transvalvular band, with a “t-tag” deployment system and suture tensioning feature.
• FIG. 52D illustrates an embodiment of a plurality of tissue anchors looped together on a suture.
• FIG. 53 is a side elevational perspective view of a transvalvular band in accordance with the present invention.
• FIG. 54 is a schematic illustration of various suture lock configurations for use on transvalvular bands of the present invention.
• FIG. 55 is a side elevational perspective view of a transvalvular band, having barbed tissue anchors thereon.
• FIG. 56 is a side elevational perspective view of a transvalvular band in accordance with the present invention, having arcuate tissue anchors thereon.
• FIGS. 56A-B are graphs illustrating data regarding chordal physiologic force experiments.
• FIG. 57 Illustrates a dilated mitral annulus with restricted posterior leaflet motion due to distortion of posterior papillary muscle due to enlargement of left ventricular chamber in ischemic or dilated cardiomyopathy. This shows malcoaptation of leaflets causing central mitral regurgitation.
• FIG. 58 is a view of the normal mitral annulus during systole looking from the left atrium to the left ventricle.
• FIG. 59 is a view of the mitral valve in ischemic and dilated cardiomyopathy in systole looking from the left atrium to the left ventricle. This shows central mitral regurgitation in the region of P2 P3 scallops of the posterior leaflet.
• FIG. 60 illustrates a transseptal catheter with cutting instrument engaged into the marginal chordae of the posterior mitral valve leaflet in ischemic dilated cardiomyopathy.
• FIG. 61 illustrates a transseptal catheter with the cutting instrument pulled back into the left atrium showing the cut marginal chordae of the posterior leaflet of the mitral valve with prolapsed posterior mitral valve leaflet into the left atrium.
• FIG. 62 illustrates a transapical catheter with chordae cutting instrument engaged in the marginal chordae of the posterior leaflet of the mitral valve.
• FIG. 63 illustrates the transmitral annular band in place across the mitral annulus, in systole, preventing the prolapse of the posterior leaflet into the left atrium. The cut marginal chordae are shown. The coaptation of the leaflet shown with no regurgitation into the left atrium during systole.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
• FIG. 1 illustrates a cross-sectional view of theheart10 with a normalmitral valve18 in systole. As illustrated, theheart10 comprises theleft atrium12 which receives oxygenated blood from thepulmonary veins14 and theleft ventricle16 which receives blood from theleft atrium12. Themitral valve18 is located between theleft atrium12 andleft ventricle16 and functions to regulate the flow of blood from theleft atrium12 to theleft ventricle16. During ventricular diastole, themitral valve18 is open which allows blood to fill theleft ventricle16. During ventricular systole, theleft ventricle16 contracts, which results in an increase in pressure inside theleft ventricle16. Themitral valve18 closes when the pressure inside theleft ventricle16 increases above the pressure within theleft atrium12. The pressure within theleft ventricle16 continues increasing until the pressure within theleft ventricle16 exceeds the pressure within theaorta20, which causes theaortic valve22 to open and blood to be ejected from the left ventricle and into theaorta20.
• Themitral valve18 comprises ananterior leaflet24 and aposterior leaflet26 that have base portions that are attached to a fibrous ring called themitral valve annulus28. Each of theleaflets24 and26 has respectivefree edges36 and38. Attached to the ventricular side of theleaflets24 and26 are relativelyinelastic chordae tendineae30. Thechordae tendineae30 are anchored topapillary muscles32 that extend from theintraventricular septum34. Thechordae tendineae30 andpapillary muscle32 function to prevent theleaflets24 and26 from prolapsing and enable proper coaptation of theleaflets24 and26 duringmitral valve18 closure. Also shown schematically is line9 through thevalve annulus28 representing the intraannular plane. Arrow8 points supraannularly, toward theleft atrium12, whilearrow7 points infraannularly, toward theleft ventricle16.
• FIG. 2 illustrates a cross-sectional view of theheart10 with a normalmitral valve18 in diastole. After theleft ventricle16 has ejected the blood into the aorta, the left ventricle relaxes, which results in a drop in pressure within theleft ventricle16. When the pressure in theleft ventricle16 drops below the pressure in theaorta20, theaortic valve22 closes. The pressure within theleft ventricle16 continues dropping until the pressure in theleft ventricle16 is less than the pressure in theleft atrium12, at which point themitral valve18 opens, as shown inFIG. 2. During the early filling phase, blood passively fills theleft ventricle16 and this accounts for most of the filling of theleft ventricle16 in an individual at rest. At the end of the filling phase, theleft atrium12 contracts and provides a final kick that ejects additional blood into the left ventricle. Also shown is intraannular plane9 as described above, and line6 representing the longitudinal axis6 of thevalve18.
• FIG. 3 illustrates a bottom view of normalmitral valve18 in systole, looking from the left atrium and to the left ventricle. As shown, theanterior leaflet24 andposterior leaflet26 are properly coapted, thereby forming acoaptive edge40 that forms a seal that prevents retrograde flow of blood through themitral valve18, which is known as mitral regurgitation.FIG. 4 illustrates a bottom view of normalmitral valve18 in diastole.FIG. 5 provides a side cross-sectional view of a normalmitral valve18 in systole. As shown inFIG. 5, thevalve leaflets24 and26 do not normally cross the plane P defined by the annulus and thefree edges36 and38 coapt together to form acoaptive edge40.
• FIG. 5 also illustrates a coaption zone41. Preferably the depth of coaption (length of zone41 in the direction of blood flow, in which theleaflets24 and26 are in contact) is at least about 2 mm or 5 mm, and is preferably within the range of from about 7 mm to about 10 mm for the mitral valve.
• Thus, implantation of the devices in accordance with the present invention preferably achieves an increase in the depth of coaption. At increase of at least about 1 mm, preferably at least about 2 mm, and in some instances an increase of at least about 3 mm to 5 mm or more may be accomplished.
• In addition to improving coaption depth, implantation of devices in accordance with the present invention preferably also increase the width of coaptation along the coaption plane. This may be accomplished, for example, by utilizing an implant having a widened portion for contacting the leaflets in the area of coaption such as is illustrated in connection withFIGS. 19A and 19B below. A further modification of the coaptive action of the leaflets which is accomplished in accordance with the present invention is to achieve early coaption. This is accomplished by the curvature or other elevation of the implant in the ventricle direction. This allows the present invention to achieve early coaption relative to the cardiac cycle, relative to the coaption point prior to implantation of devices in accordance with the present invention.
• FIGS. 4 and 6 illustrate normalmitral valve18 in diastole. As shown, theanterior leaflet24 andposterior leaflet26 are in a fully opened configuration which allows blood to flow from the left atrium to the left ventricle.
• FIGS. 7 and 8 illustrate aheart10 in systole where theanterior leaflet24 of themitral valve18 is in prolapse.Anterior leaflet24 prolapse can be caused by a variety of mechanisms. For example, as illustrated inFIG. 7, rupture42 of a portion of thechordae tendineae30 attached to theanterior leaflet24 can cause thefree edge36 of theanterior leaflet24 to invert duringmitral valve18 closure. As shown inFIG. 8, inversion44 of theanterior leaflet24 can prevent themitral valve leaflets24 and26 from properly coapting and forming a seal. This situation where thefree edge36 of theanterior leaflet24 crosses into theleft atrium12 duringmitral valve18 closure can lead to mitral regurgitation.
• Similarly,FIGS. 9 and 10 illustrateposterior leaflet26 prolapse caused by a rupture of thechordae tendineae30 attached to theposterior leaflet26. In this case, theposterior leaflet26 can invert and cross into theleft atrium12 duringmitral valve18 closure. The inversion of theposterior leaflet26 prevents themitral valve leaflets24 and26 from properly coapting and forming a seal, which can lead to mitral regurgitation.
• Mitral regurgitation can also be caused by anelongated valve leaflet24 and26. For example, an elongatedanterior leaflet24, as shown inFIG. 11, can prevent thevalve leaflets24 and26 from properly coapting duringmitral valve18 closure. This can lead to excessive bulging of theanterior leaflet24 into theleft atrium12 and misalignment of thefree edges36 and38 during coaptation, which can lead to mitral regurgitation.
• One embodiment of atransvalvular band50 that would improvemitral valve leaflet24 and26 coaptation and prevent or reduce mitral regurgitation is illustrated inFIGS. 12 and 13.FIG. 12 provides a top view of thetransvalvular band50 whileFIG. 13 provides a side view of thetransvalvular band50. In this embodiment, thetransvalvular band50 comprises an elongate and curved structure with afirst end52, asecond end54, acentral portion64 located between the two ends52 and54, and a length that is capable of extending across the annulus. Theleaflet contact surface56 is convex along the longitudinal axis, as best illustrated inFIG. 13. In other embodiments, theleaflet contact surface56 can have a different shape and profile. For example, thecontact surface56 can be concave, straight, a combination of convex, concave and/or straight, or two concave or straight portions joined together at an apex. As illustrated inFIG. 12, thetransvalvular band50 can have a substantially constant width between thefirst end52 and thesecond end54. Thefirst end52 has afirst anchoring portion58 and thesecond end54 has asecond anchoring portion60.
• The anchoringportions58 and60 can haveholes62 for sutures that allow thetransvalvular band50 to be secured to the annulus. Alternatively, in other embodiments the anchoringportions58 and60 can have other means for securing thetransvalvular band50 to the annulus. For example, the anchoringportions58 and60 can be made of a membrane or other fabric-like material such as Dacron or ePTFE. Sutures can be threaded directly through the fabric without the need fordistinct holes62. The fabric can be attached to the other portions of thetransvalvular band50 by a variety of techniques. For example, the fabric can be attached to the other portions of thetransvalvular band50 with the use of an adhesive, by suturing, by tying, by clamping or by fusing the parts together. Another non-limiting technique of securing the transvalvular band to the annulus is to coat a malleable metal basis material, which creates structure for securing a skeleton of the transvalvular band, with a polymer such as silicone and bonding a material, such as PET (i.e., Dacron) velour for comprehensive tissue ingrowth when desired.
• The central portion of thetransvalvular band50 can have a variety of cross-sectional shapes, as illustrated inFIGS. 14-17. For example, the cross sectional shape can be substantially rectangular, circular, oblong or triangular. The edges of thetransvalvular band50 can be rounded or otherwise configured so that thetransvalvular band50 presents anatraumatic surface51 to the valve leaflets. In some embodiments, the cross-section can be oriented in a particular fashion to enhance performance of thetransvalvular band50. For example as shown inFIG. 14, atransvalvular band50 with a triangular cross section can be designed so that a relativelylarger surface56 of the triangle contacts the valve leaflets while a lowerprofile leading edge53 of the triangle opposite thesurface51 faces the left atrium. This configuration allows a larger surface area to make contact with and support the mitral valve leaflets, while also presenting a more streamlined shape that provides less resistance to blood flowing from the left atrium to the left ventricle. Decreasing the resistance to blood flow is desirable because it can reduce turbulence and reduce the impedance of thetransvalvular band50 on the filling of the left ventricle. Similarly, thetransvalvular bands50 with an oblong or rectangular cross-section can be oriented to either increase the surface area for contact with the valve leaflets, or be oriented to reduce the resistance to blood flow.
• The dimensions of thetransvalvular band50 will vary, depending upon the specific configuration of theband50 as well as the intended patient. In general,transvalvular band50 will have an axial length fromfirst end52 tosecond end54 within the range of from about 20 mm to about 32 mm. In one embodiment, intended for a typical male adult, the axial length of thetransvalvular band50 is about 24 mm to 26 mm. The width of thetransvalvular band50 in thecentral zone64 may be varied depending upon the desired performance, as will be discussed herein. In general, the trailingsurface51 against which leaflets will seat is preferably large enough to minimize the risk of erosion resulting from repeated contact between the closed leaflets and the implant. The width of the leadingedge53 is preferably minimized, as discussed above, to minimize flow turbulence and flow obstruction. In general, widths of thesurface51 measured perpendicular to the flow of blood are presently contemplated to be less than about 5 mm, and often within the range of from about 5 mm to about 10 mm in the zone of coaptation.
• In some embodiments as illustrated inFIG. 18, thecentral portion64 of thetransvalvular band50 can be narrower in width, measured perpendicular to blood flow than the first andsecond anchoring portions58 and60. By narrowing thecentral portion64, the resistance to blood flow can be reduced. However, narrowing thecentral portion64 reduces the surface area of theleaflet contact surface56 that supports the valve leaflets.
• In the embodiment illustrated inFIG. 18, the narrowedcentral portion64 is separated from thefirst anchoring portion58 and second anchoringportion60 by a first shoulder57 and second shoulder59. The length of thecentral portion64, between first shoulder57 and second shoulder59 can be less than about 50% of the overall length of the device, or less than about 30% of the overall length of the device if it is desired to minimize the obstruction in the center of the flow path, while presenting a wider transverse surface for supporting the leaflets when the valve is closed. Alternatively, the length of thecentral zone64 may be greater than 50%, and in some embodiments greater than 75% of the overall length of the implant.
• In some embodiments as illustrated inFIGS. 19A,19B,21 and23, a coaptiveedge support portion66 of thecentral portion64 of thetransvalvular band50 can be wider than the adjacent portions of thetransvalvular band50, leading up to and potentially including the first andsecond anchoring portions58 and60. By increasing the width and surface area of the coaptiveedge support portion66, more support can be provided to the valve leaflets at the coaptive edge. This increased support can increase the width of leaflet coaption. The other portions of thecentral portion64 can remain narrow to reduce the resistance to blood flow. Thesupport portion66 can be located at a fixed position or adjustable along the transvalvular band so that its position can be optimized by the surgeon and then secured at a fixed point such as by suturing, or removed if deemed unnecessary.
• In one implementation of the invention, the transvalvular band comprises a first component for primary reduction and a second component for fine adjustment. For example, the device illustrated inFIG. 19A may be provided with an adjustable (e.g. slidable)support portion66. The transvalvular band may be positioned across the annulus as has been described herein, and hemodynamic function of the valve may be evaluated. Thesupport portion66 may thereafter be adjusted along the length of the transvalvular band to treat residual leakage or otherwise optimize the functionality of the implant such as by increasing the zone of coaptation. The second component (e.g. support portion66) may thereafter be fixed with respect to the transvalvular band such as by sutures, clips, adhesives, or other techniques known in the art. Alternatively, the second portion may be separate from and connectable to the transvalvular band such as stitching, clips, suturing or other technique known in the art.
• In addition, the coaptiveedge support portion66 can be offset from the center of thetransvalvular band50, to reflect the asymmetry between the anterior leaflet and the posterior leaflet. For example, the coaptiveedge support portion66 can be positioned closer to thefirst anchoring portion58 than to thesecond anchoring portion60. In certain embodiments, theedge support portion66 will be centered about a point which is within the range of from about 20% to about 45% of the overall length of the implant from the closest end.
• FIG. 20 illustrates another embodiment of atransvalvular band50 that is a modification of thetransvalvular band50 shown inFIG. 18. As illustrated inFIG. 20, thetransvalvular band50 has a narrowcentral portion64 that provides relatively low resistance to blood flow. However, the first andsecond anchoring portions58 and60 extend further in a lateral direction, and can be arcuate to conform to the mitral valve annulus. These laterally extended anchoringportions58 and60 provide additional anchoring of thetransvalvular band50 and can help improve the stability of the device after implantation. The laterally extending anchoringportion58 and60 may be provided with any of a variety of structures for facilitating anchoring to the valve annulus. For example, they may be provided with a plurality ofapertures61, for conventional stitching or to receive any of a variety of clips or tissue anchors. The anchoring portions may alternatively be provided with any of a variety of barbs or hooks, or may be provided with a fabric covering such as a Dacron sleeve to facilitate sewing. Further, in some embodiments, this sewing ring may have an elastomeric core upon which the Dacron is secured to provide a more compliant structure to hold the implant. Measured in the circumferential direction (transverse to the longitudinal axis of the implant50) the laterally extending anchoring portions will have an arc length of greater than about 5 mm, and, in some embodiments, greater than about 1 cm. Arc lengths of at least about 2 cm, and, in some embodiments, at least about 3 cm may be utilized, depending upon the desired clinical performance.
• FIG. 21 illustrates another embodiment of atransvalvular band50 with theextended anchoring portions58 and60 and a wider, offset coaptiveedge support portion66. This embodiment has the benefit of additional stability provided by theextended anchoring portions58 and60 and enhanced support of the coaptive edge.
• FIGS. 22 and 23 illustrate another embodiment of atransvalvular band50 which is combined with anannular ring68. Theannular ring68 can be used as both a support for thetransvalvular band50 and, if desired, also to help stabilize the size and shape of the mitral valve annulus itself. In some embodiments, theannular ring68 can be used to reduce the size of the mitral valve annulus and to bring the mitral valve leaflets closer together. This can be accomplished by, for example, suturing the mitral valve annulus to anannular ring68 of smaller diameter. In addition, theannular ring68 provides additional support and stability to thetransvalvular band50. The anchoringportions58 and60 of thetransvalvular band50 can be formed integrally with theannular ring68, or the anchoringportions58 and60 can be attached to the annular ring by a variety of means, such as suturing, bonding, adhesives, stapling and fusing.FIG. 22 discloses an embodiment with a narrowcentral portion64 whileFIG. 23 discloses an embodiment with a wider, offset coaptiveedge support portion66.
• FIG. 23A illustrates a further implementation of the invention, adapted to treat ischemic mitral regurgitation with posterior annuloplasty. Atransvalvular band61 is provided for spanning the leaflet coaption plane as has been described herein. Any of the features described in connection with other transvalvular bands disclosed herein may be incorporated into thetransvalvular band61.
• An arcuateposterior annuloplasty support63 is connected to thetransvalvular band61, and adapted to extend for an arc length along the native annulus. In the illustrated embodiment, thesupport63 extends through an arc of approximately 180°, extending from a firsttrigone attachment zone65 to a secondtrigone attachment zone67. The attachment zones may be provided with sewing apertures, a fabric covering, or other structure for facilitating attachment to tissue. In general, thetransvalvular band61 will have dimensions similar to those described elsewhere herein. The transverse dimension fromfirst trigone zone65 tosecond trigone zone67 may be varied depending upon the size of the native annulus, but will generally be within the range of from about 35 mm to about 45 mm.
• Referring toFIG. 23B, there is illustrated a transvalvular band in accordance with the present invention, formed from a single length or several lengths of flexible wire. The bend angles and orientation of the struts in the illustrated embodiment may be readily altered, to accommodate the desired axes of compression which may be desirable for a particular deployment procedure.
• In general, thetransvalvular band71 comprises an elongateflexible wire73 formed into a serpentine pattern, for providing a support for the valve leaflets as has been discussed herein. Although not illustrated inFIG. 23B, thewire73 may be formed such that it bows or inclines in the direction of the ventricle to achieve early closure as is discussed elsewhere herein. Thewire73 may extend into afirst connection section75 and asecond connection section77. Each of theconnection sections75 and77 may be provided with a plurality ofeyelets79, to receive sutures for attaching the implant to the valve annulus. The implant may be formed from any of a variety of flexible materials, including various polymers described elsewhere herein as well as titanium, titanium alloy, Nitinol, stainless steel, elgiloy, MP35N, or other metals known in the art. This design has an advantage of providing a relatively large support footprint against the valve leaflets, while at the same time optimizing the area of open space to permit maximum blood flow therethrough. The design may be treated or coated with silicone or other suitable material to eliminate untoward effects such as thrombosis or corrosion. Treatments may be sequential and include more than one listed but not limited to electropolishing, harperization, tumbling, pickling, plating, encapsulation or physical vapor deposition of appropriate materials.
• FIGS. 24-27 illustrate side views oftransvalvular bands50 with different inclinations. One of the objectives of the present invention is to not merely provide support to the leaflets during systole, but to elevate the plane of coaption in the direction of the ventricle, to cause early coaption (closure) relative to the cardiac cycle, as is discussed elsewhere herein. The variation in conditions, and other patient to patient variations may warrant production of the transvalvular band of the present invention in an array of sizes and/or configurations, so that clinical judgment may be exercised to select the appropriate implant for a given case. Alternatively, the transvalvular band may be provided in an adjustable form or a modular form so that an implant of the desired configuration can be constructed or modified intraoperatively at the clinical site. In a three segment embodiment, such as that illustrated inFIGS. 24 through 27, a central segment may be provided for positioning within the center of the flow path, or centered on the coaptive edges of the leaflets. First and second end portions may be connected to the central portion, for supporting the central portion relative to the tissue anchors. First and second end portions may be provided in a variety of lengths and curvatures, enabling construction of a relatively customized modular implant as may be desired for a particular patient.
• For example,FIG. 24 illustrates atransvalvular band50 with acentral portion64 and two gentlyangled arm portions70 and72. The first and second ends52 and54 are displaced from thecentral portion64 by a height, h1 and h2, respectively. InFIG. 24, h1 and h2 are about equal and can range from about 0 mm to about 10 mm. Preferably h1 and h2 will be at least about 2 mm and will often be at least about 4 mm or 6 mm or more, but generally no more than about 10 mm or 12 mm.
• FIG. 25 illustrates atransvalvular band50 with acentral portion64 and two sharplyangled arm portions70 and72. The first and second ends52 and54 are displaced from thecentral portion64 by a height, h1 and h2, respectively. InFIG. 25, h1 and h2 are about equal and can range from about 8 mm to about 12 mm.FIG. 26 illustrates atransvalvular band50 with acentral portion64, a highly angledfirst arm70 and a gently angledsecond arm72. The first and second ends52 and54 are displaced from thecentral portion64 by a height, h1 and h2, respectively. InFIG. 26, h1 is greater than h2. The h1 ranges from about 6 mm to about 10 mm, while h2 ranges from about 2 mm to about 6 mm.FIG. 27 illustrates atransvalvular band50 with acentral portion64, a gently angledfirst arm70 and a highly angledsecond arm72. The first and second ends52 and54 are displaced from thecentral portion64 by a height, h1 and h2, respectively.FIG. 27, may be a mirror image ofFIG. 26.
• Thetransvalvular band50 can be made of any of a variety of materials that are compatible with implantation within a patient's body and which has the requisite structural integrity to support the mitral valve leaflets. For example, suitable materials include titanium, titanium alloys, stainless steel, stainless steel alloys, nitinol, elgiloy, MP35N, other metals and alloys, ceramics, and polymers such as PTFE, polycarbonate, polypropylene, UHMWPE, HDPE, PEEK, PEBAX and the like.
• In order to reduce the thrombogenicity of thetransvalvular band50, thetransvalvular band50 can be provided with a smooth surface or appropriately micro-texture the surface in some embodiments, such as via a porous or microporous structure. Other factors such as surface chemistry, energy, morphology, macrofeatures, and general material properties matching the in situ needs can also be considered in tailoring the surface of the band. In addition, thetransvalvular band50 can be coated with a variety of substances to reduce thrombogenicity. For example, thetransvalvular band50 can be coated with a antithrombogenic agent such as heparin, a polymer such as PTFE, or a polymer conjugated with heparin or another antithrombogenic agent. Heparin coatings can be achieved in a variety of methods, one of which may be to coat or drip the prosthesis in TDMAC-heparin (Tridodecylmethylammonium heparinate).
• As illustrated inFIGS. 28-31, thetransvalvular band50 is implanted in the plane of themitral valve annulus28 in a patient suffering fromanterior leaflet26 prolapse caused by therupture42 of thechordae tendineae30 attached to theanterior leaflet26. Although a prolapsedanterior leaflet26 is illustrated, it should be understood that the method described herein is also applicable for treating other types of prolapse, such as posterior leaflet prolapse and prolapse caused byelongated leaflets24 and26. Thetransvalvular band50 can be attached to theannulus28 by a variety of techniques, such as sutures, anchors, barbs, stapes, self-expanding stents, or other techniques that are known or are apparent to those of skill in the art.
• As best illustrated inFIGS. 29 and 31, thetransvalvular band50 is oriented in theannulus28 so that thetransvalvular band50 is positioned approximately transversely to thecoaptive edge42 formed by the closure of themitral valve leaflets24 and26. Thetransvalvular band50 can also be positioned over the prolapsed portion of theanterior leaflet26 so that thetransvalvular band50 can directly support the prolapsed portion of theanterior leaflet24 and keep theanterior leaflet24 inferior to the plane of themitral valve annulus28, i.e., elevated in the direction of the ventricle or of antegrade flow, thereby preventing or reducing prolapse and mitral regurgitation.
• FIGS. 28 and 29 illustrate the effect of thetransvalvular band50 on themitral valve18 during systole. As shown, both theanterior leaflet24 and theposterior leaflet26 are supported by the transvalvular band during closure of themitral valve18. Thearcuate transvalvular band50 functions to keep bothleaflets24 and26 inferior to the plane of theannulus28 and enables theleaflets24 and26 to form acoaptive edge40. Although asingle transvalvular band50 has been illustrated, in some embodiments, multipletransvalvular bands50 such as two or three or more can be implanted across theannulus28 to provide additional support to themitral valve leaflets24 and26.
• FIGS. 30 and 31 illustrate the effect of thetransvalvular band50 on themitral valve18 during diastole. During diastole, themitral valve18 opens so that blood can fill theleft ventricle16 from theleft atrium12. As best illustrated inFIG. 31, thetransvalvular band50 obstructs only a small portion of themitral valve18 opening, and therefore, does not cause excessive resistance to blood flow.
• FIGS. 32-35 are cross-sectional side views of themitral valve18 with and without the support of thetransvalvular band50. During systole, themitral valve18 closes. Without thetransvalvular band50, theanterior leaflet24 crosses the plane P defined by themitral valve annulus28 and prolapse, which leads to mitral regurgitation, as shown inFIG. 33. However, by implanting thetransvalvular band50 in theannulus28 such that thearcuate transvalvular band50 arches towards the left ventricle and thecentral portion64 is displaced from the plane P, theanterior leaflet24 is prevented from prolapsing above the plane P thus eliminating or reducing retrograde flow (shown inFIG. 33). Theleaflets24 and26 rest upon thetransvalvular band50 and the pressure exerted by the blood upon the distal portion of theleaflets24 and26 form thecoaptive edge40. As illustrated inFIGS. 34 and 35, the performance of themitral valve18 during diastole is not substantially affected by thetransvalvular band50.
• Although the method of implanting and positioning thetransvalvular band50 has been illustrated with one embodiment of thetransvalvular band50, other embodiments as described above can also be used. For example,FIG. 36 illustrates atransvalvular band50 with a wider, offset coaptiveedge support portion66 that has been implanted in the mitral valve annulus. As shown, thecoaptive edge support66 is offset so that it positioned to support the coaptive edge of themitral valve18. In addition, thetransvalvular band50 can be used in conjunction with other devices and procedures, such as a separate or integrally attached annular or annuloplasty ring described above. In addition, thetransvalvular band50 can be used in conjunction with the Alfieri procedure, where the tips of themitral valve leaflets24 and26 are sutured74 together, as shown inFIG. 38.
• Referring toFIG. 37, there is illustrated a perspective view of atransvalvular band50 having a transverse projection orsupport51 extending in the direction of the ventricle or in the direction of diastolic blood flow, which could be considered antegrade. Thesupport51 has a width W, which may be at least about 3 mm, and in some embodiments, at least about 5 mm, and in other embodiments at least about 1.0 cm. Theprojection51 may be utilized without an Alfieri stitch, so that the leaflets of the mitral valve close against opposingside walls53 and55 of theprojection51. Theprojection51 thus helps center the closure of the leaflets, as well as controlling the width of coaption. In addition, theband50 is illustrated as convex in the direction of the ventricle, to accomplish early closure as has been discussed herein.
• The transvalvular band in accordance with the present invention can be implanted via an open surgical procedure, via thoracotomy (e.g. transapically) or alternatively, via a percutaneous procedure using a translumenally implantable embodiment. In the translumenally implantable embodiment, one or more transvalvular bands can be attached to a self-expandable support structure, such as a self-expandable ring or self-expandable stent having a relatively short axial length relative to its expanded diameter. The transvalvular band and the compressed self-expandable support structure are loaded into a catheter with a retractable outer sheath which is inserted percutaneously and advanced translumenally into or across the mitral valve. The retractable outer sheath can be retracted to allow the self-expandable support structure to expand adjacent or against the annulus, thereby positioning the one or more transvalvular bands in about the plane of the mitral annulus. Each transvalvular band can be characterized by a longitudinal axis, and the transvalvular band is oriented in the mitral valve such that the longitudinal axis of the transvalvular band in oriented substantially transversely to the coaptive edge of the mitral valve.
• By “percutaneous” it is meant that a location of the vasculature remote from the heart is accessed through the skin, such as using needle access through, for example, the Seldinger technique. However, it may also include using a surgical cut down procedure or a minimally invasive procedure. The ability to percutaneously access the remote vasculature is well-known and described in the patent and medical literature.
• Depending on the point of vascular access, the approach to the mitral valve may be antegrade and require entry into the left atrium via the pulmonary vein or by crossing the interatrial septum. Alternatively, approach to the mitral valve can be retrograde where the left ventricle is entered through the aortic valve. Once percutaneous access is achieved, the interventional tools and supporting catheter(s) will be advanced to the heart intravascularly where they may be positioned adjacent the target cardiac valve in a variety of manners, as described elsewhere herein. While the methods will preferably be percutaneous and intravascular, many of the implants and catheters described herein will, of course, also be useful for performing open surgical techniques where the heart is beating or stopped and the heart valve accessed through the myocardial tissue. Many of the devices will also find use in minimally invasive procedures where access is achieved thorascopically and where the heart will usually be stopped but in some instances could remain beating.
• A typical antegrade approach to the mitral valve is depicted inFIG. 39. The mitral valve MV may be accessed by a standard approach from the inferior vena cava IVC or superior vena cava SVC, through the right atrium RA, across the interatrial septum IAS and into the left atrium LA above the mitral valve MV. As shown, acatheter120 having aneedle122 may be advanced from the inferior vena cava IVC into the right atrium RA. Once thecatheter120 reaches the interatrial septum IAS, theneedle122 may be advanced so that it penetrates through the septum at the fossa ovalis FO or the foramen ovale into the left atrium LA. At this point, a guidewire may be advanced out of theneedle122 and thecatheter120 withdrawn.
• As shown inFIG. 40, access through the interatrial septum IAS will usually be maintained by the placement of aguide catheter125, typically over aguidewire124 which has been placed as described above. Theguide catheter125 affords subsequent access to permit introduction of the tool(s) which will be used for performing the valve or tissue modification, as described in more detail below.
• A typical retrograde approach to the mitral valve is depicted inFIG. 41. Here the mitral valve MV may be accessed by an approach from the aortic arch AA, across the aortic valve AV, and into the left ventricle below the mitral valve MV. The aortic arch AA may be accessed through a conventional femoral artery access route, as well as through more direct approaches via the brachial artery, axillary artery, or a radial or carotid artery. As shown inFIG. 42, such access may be achieved with the use of aguidewire128. Once in place, aguide catheter126 may be tracked over theguidewire128. Theguide catheter126 affords subsequent access to permit introduction of the tool(s) which will be used for performing the valve modification, as described in more detail below.
• In some cases, access routes to the mitral valve may be established in both antegrade and retrograde approach directions. This may be useful when, for instance, grasping is performed with the use of specific devices introduced through one route and fixation is achieved with the use of separate devices introduced through another route. In one possible situation, the transvalvular band may be introduced via a retrograde approach. While the transvalvular band is held in place, a fixation tool may be introduced via an antegrade approach to fix the transvalvular band in place. The access pathways for the transvalvular band and fixation tool may alternatively be reversed. Thus, a variety of access routes may be used individually or in combination with the methods and devices of the present invention.
• Referring toFIG. 43A, there is illustrated a schematic view of a percutaneously deliverable implant in accordance with one aspect of the present invention. The deployment system includes adeployment catheter200, only a distal end of which is illustrated herein.Deployment catheter200 is configured in accordance with known technology for accessing the mitral valve, utilizing conventional dimensions and the materials known to those of skill in the art. In general, thedeployment catheter200 comprises an elongate flexibletubular body202 extending between a proximal end (not illustrated) and adistal end204. The proximal end is provided with a proximal manifold, including access portals such as luer connectors in communication with each functional lumen in thecatheter200.
• Thedistal end204 is provided with adistally facing opening208, which is in communication with the proximal end via acentral lumen206.
• Positioned within thecentral lumen206 is acollapsed implant210.Implant210 is transformable between a first, radially reduced configuration such as for positioning within thedeployment catheter200 and a second, radially enlarged configuration (seeFIG. 43C) for positioning at the treatment site. Transformation of the implant from the first configuration to the second configuration may be accomplished under positive force, such as via balloon dilatation. Alternatively, as illustrated herein, transformation is accomplished by self-expansion of theimplant210 in response to removal of the constraint provided by thetubular body202.
• In general, theimplant210 comprises a frame oranchor component212 and aleaflet support component214.Leaflet support component214 may comprise any of a variety of structures similar to those described previously herein as the annular band, configured or reconfigured such that the annular band may be radially reduced for positioning within a deployment catheter and subsequently radially enlarged for spanning the mitral valve. Theimplant210 additionally comprises an anchor component, for anchoring theleaflet support214 at the treatment site. In the illustrated embodiment,anchor212 is schematically illustrated as a zigzag wire or filament structure, which is radially expansible following removal of the constraint. However, any of a variety of configurations may be utilized for theanchor212.
• Referring toFIG. 43B, the outer tubularflexible body202 is shown partially retracted from the implant, permitting the implant to begin to radially expand.FIG. 43C illustrates further retraction of thetubular body202, to fully release theanchor212 at the deployment site. As illustrated,anchor212 radially expands within the left atrium. Theleaflet support214 extends approximately transversely to the coaptive edge of the mitral valve leaflets, and is convex or inclined in the direction of the mitral valve to advance the coaptation of the mitral valve leaflets in the direction of the ventricle as has been described elsewhere herein.
• As seen inFIG. 43A, theimplant210 is controlled by at least onecontrol line216.Control line216 extends throughout the length of thedeployment catheter200, and to at least one control on or near the proximal manifold. This enables proximal retraction of theflexible body202 with respect to theimplant210, and control ofimplant210 prior to final detachment from the deployment system.
• Referring toFIG. 43C, at least afirst control wire216, asecond control wire218, and a third control wire220 are illustrated connected to theanchor212.Control wires216,218 and220 enable manipulation of the implant into its final desired position, and, if necessary, proximal retraction of the implant back within the deployment catheter should the decision be made to remove the implant prior to final detachment.
• Prior to final detachment of theimplant210, additional anchoring structures may be engaged to retain the implant at its desired implanted location. For example,anchor212 may be provided with any of a variety of tissue anchors or barbs, for engaging the mitral valve annulus or the base of the leaflets or other adjacent anatomical structures. Alternatively, separate tissue anchors may be advanced through thedeployment catheter200, and utilized to secure theanchor212 to the adjacent tissue. Suitable anchors are preferably enlargeable from a first, reduced cross sectional configuration for traveling through thedeployment catheter200 and piercing tissue, to a second, enlarged configuration for resisting removal from the tissue. In the embodiment illustrated inFIG. 43C, no secondary anchoring structures are illustrated for simplicity.
• Once the position of theimplant210 has been verified and found acceptable, and the determination of whether to introduce secondary anchoring structures has been made, thecontrol wires216,218 and220 are detached from theanchor212, and thedeployment catheter200 is removed from the patient. Detachment of the control wires from theimplant210 may be accomplished in any of a variety of ways, such as by electrolytic detachment, detachment by thermal elevation of a softenable or meltable link, mechanical detachment such as by rotating the control wire such that a threaded end of the control wire is threadably disengaged from theanchor212, or other detachment techniques depending upon the desired functionality and profile of the system.
• Referring toFIG. 43D, there is illustrated a side elevational view of theimplant210 in an unconstrained (e.g., bench top) expanded configuration. Theanchor210 comprises a plurality ofstruts222, which are joined at a first end by a plurality ofapices224 and a second end by a plurality ofapices226 to produce a zigzag structure sometimes referred to as a “Z stent” configuration. This configuration is convenient and well understood in the intravascular implant arts, although any wide variety of structures may be utilized. For example, zigzag wire patterns, woven wire patterns, or sinusoidal wire patterns may be utilized. Laser cut wall patterns such as from tubing stock may also be utilized, and may be provided with any of a wide variety of complex wall patterns. In general, nickel titanium alloys such as any of a variety of nitinol alloys are preferred. However, depending upon the wall pattern, stainless steel, elgiloy, certain polymers or other materials may also be utilized. Heat treatment may be required to anneal and shape set an alloy such as Nitinol. Other alloys may require only annealing to relieve stresses incurred during prior processing.
• Referring toFIG. 43E, there is illustrated an end view of the implant shown inFIG. 43D to show the transverse configuration of the transvalvular band portion of the implant. In this illustration, the transvalvular band comprises a plurality ofstruts230 which are connected to theanchor212 atjunctions232.Struts230 may in turn be divided into a bifurcated section234 or other configuration to increase the effective footprint of the transvalvular band measured along the coaptive edge of the valve, while minimizing obstruction to blood flow therethrough. The coaptive edge of the valve, as implanted, will preferably be approximately aligned with thetransverse axis236 illustrated inFIG. 43E of the band, as implanted. The axis of coaption of the mitral valve is preferably parallel toaxis236 in the implanted configuration, but may be within about 45°, preferably within about 20°, and most preferably within about 10° of theaxis236.
• Referring toFIGS. 44A and 44B, there is illustrated an anchor deployment catheter which may be utilized to provide either primary or secondary anchoring of theanchor structure212 to adjacent tissue.Anchor deployment catheter250 comprises an elongate flexibletubular body252, configured to access the vicinity of the mitral valve.Tubular body252 extends between aproximal end254 and a distal end256. Distal end256 is provided with adistal opening258, enabling access to acentral lumen260. An elongateflexible core wire262 extends from theproximal end254 throughout most of the length of thelumen260 to adistal surface264. SeeFIG. 44C. The proximal end of thecore wire262 is provided with acontrol266 that enables axial reciprocal movement of thecore wire262 within thecentral lumen260.
• Atissue anchor268 may be positioned within the distal end of thedelivery catheter250. In use, manipulation of thecontrol266, such as by distal axial advance relative to thetubular body252, distally, axially advances thecore wire262 to expel theanchor268 through thedistal opening258.Distal opening258 is preferably provided with a bevel or angled cut to provide a sharpeneddistal tip270. This enables distal axial advance of thedistal tip270 into tissue at a desired site, so that thecontrol266 may be manipulated to deploy all or a portion of theanchor268 into the target tissue.
• Any of a variety of tissue anchors268 may be utilized, depending upon the desired configuration of the implant and the implant anchor interface. In the illustrated embodiment, theanchor268 is configured as a double “t-tag” anchor. A firsttissue engaging element272 is connected to a secondimplant engaging element274 by afilament276. In use, thedistal tip270 is positioned within the tissue of the mitral valve annulus.Control266 is manipulated to deploy thefirst element272 beneath the surface of the tissue. Thetubular body252 is thereafter proximally retracted, enabling thesecond element274 to engage the implant and retain it against the adjacent tissue.
• Theanchor delivery catheter250 may be advanced through thedeployment catheter200, and/or along a guide such as a guidewire or support wire. In the illustrated embodiment, theanchor deployment catheter250 is provided with aguide lumen278 allowing the anchor delivery catheter to track along a guidewire.Guide lumen278 is defined by atubular wall280.Tubular wall280 may extend the entire length of theanchor delivery catheter250, such as by forming the catheter body as a dual lumen extrusion. Alternatively,tubular wall280 may be provided with an axial length that is short relative to the overall length of the catheter, such as no more than about 3 cm and preferably no more than about 2 cm in length. This allows the anchor delivery catheter to ride along a guidewire in a monorail or rapid exchange manner as will be illustrated below.
• Referring toFIGS. 45A and 45B, there is illustrated an implant configured for use with the anchor delivery catheter described above. In general, the implant comprises afirst leaflet support292 and asecond leaflet support294, separated by aflexible connection296.Flexible connection296 permits theimplant290 to be folded within a deployment catheter, and later expanded in a manner that permits theimplant290 to function as a transvalvular band as described. Theimplant290 may be manufactured in any of a variety of ways, such as using a wire frame or by laser cutting from sheet stock as will be appreciated by those of skill in the art.
• In the illustrated embodiment, a first and secondflexible connection296 reside in a plane configured to be substantially parallel to the axis of coaption the as implanted orientation. The lateral edges of the each of thefirst leaflet support292 andsecond leaflet support294 are provided with at least one and preferably two or threeeyes298, fabric patches, or other anchor attachment structure, for receiving a tissue anchor.
• Referring toFIG. 45B, the implant ofFIG. 45A is illustrated in a partially collapsed configuration, flexed about theflexible connection296. In addition,control wires300,302 and304 are illustrated releasably connected to theimplant290.Control wires300,302 and304 may be utilized to advance theimplant290 from the deployment catheter such ascatheter200 described above, and manipulate the implant until the anchors have been fully deployed. Thereafter,control wires300,302 and304 may be removed such as by electrolytic detachment, melting a polymeric link, unscrewing a threaded connection, or other detachment mechanism depending upon the desired functionality of the device.
• Referring toFIGS. 46A through 46E, there is illustrated a sequence of deploying an implant at the mitral valve from an antegrade direction. Theimplant290 may be similar to that illustrated inFIGS. 45A and 45B, or have wall patterns or characteristics of other implants disclosed elsewhere herein. In general, theimplant290 is deployed from thecatheter200 in the sequence illustrated inFIGS. 46A through 46C. The surrounding anatomy has been eliminated for simplicity.
• Referring toFIG. 46D, theanchor delivery catheter250 is advanced onto the proximal end of one of thecontrol wires300, such that thecontrol wire300 is axially moveably positioned withinguide lumen278. This enables theanchor delivery catheter250 to be advanced along thecontrol wire300 in a monorail or rapid exchange configuration as is understood in the catheter arts.Anchor delivery catheter250 is advanced along thecontrol wire300 until thedistal tip270 advances through theeye298 or fabric tab or other attachment structure, and into the adjacent tissue of the base of the mitral valve leaflet or mitral valve annulus. Thecontrol266 is manipulated such as by distal advance to advance thefirst anchor element272 out of thedistal opening258 and into the tissue as illustrated inFIG. 46D.
• Theanchor delivery catheter250 is thereafter proximally withdrawn to position thedistal opening258 on the device proximal side of theeye298, and thecore wire262 is further distally advanced to deploy thesecond anchor element274 from thedistal opening258 of theanchor delivery catheter250.Anchor delivery catheter250 may thereafter be proximally withdrawn from the patient. Either the same or a differentanchor delivery catheter250 may thereafter be advanced along thethird control wire304, enabling deployment of another tissue anchor as is illustrated inFIG. 46E.
• Theimplant290 is illustrated inFIG. 46E as having a central portion inclined in the direction of the ventricle to support the leaflets as has been discussed elsewhere herein. This configuration may be retained by the inherent bias built into the structure and materials of theimplant290. Alternatively, the configuration of inclining in the direction of the ventricle may be retained by active intervention such as by providing a mechanical interlock, in situ heat weld with capacitive discharge/electrolytic weld, application of a clip or other locking structure by way ofcontrol wire302 or simply by the mechanical forces attributable to the mitral valve annulus, which prohibit lateral expansion of the device sufficient for theflexible connection296 to invert in the direction of the atrium. Alternatively, an implantable control wire (not illustrated) may be introduced, to connect theimplant290 such as in the vicinity of theflexible connection296 to the opposing wall of the ventricle, as will be described in connection with a transapical implementation of the invention described below.
• A further implementation of the invention is illustrated in connection withFIGS. 47A through 47E. Referring toFIG. 47A, thefirst control line300 andthird control line304 have been replaced by afirst guide tube310 and asecond guide tube312.First guide tube310 andsecond guide tube312 each has the double function of controlling deployment of the implant, as well as enabling introduction of a tissue anchor therethrough. This avoids the use of a separate tissue anchor deployment catheter such as that described above.
• As illustrated inFIG. 47B, once the implant is provisionally positioned in the vicinity of the mitral valve, afirst tissue anchor314 is deployed through thefirst guide tube310. Asecond tissue anchor316 is deployed through thesecond guide tube312. The tissue anchors may comprise “T” tag type constructions, pigtail or corkscrew constructions, or any of a variety of other soft tissue anchors known in the art. In general, tissue anchors utilized for the present purpose are preferably transformable from a first, reduced cross-sectional configuration to a second, radially enlarged cross-sectional configuration to enable deployment through a small needle or tube and then provide a relatively higher resistance to pull out. Radial enlargement may be accomplished by angular movement of a portion of the anchor, or by physical expansion in a radial direction.
• Referring toFIG. 47C, thefirst guide tube310 andsecond guide tube312 have been removed following deployment of the tissue anchors. The guide tubes may be removed using any of a variety of detachment techniques disclosed elsewhere herein. Either before or after removal of the guide tubes, distal pressure on either thetubular body202 or thecontrol wire302 inverts the implant from the configuration shown inFIG. 47C to the final configuration shown inFIGS. 47D and E. The inverted configuration ofFIGS. 47D and E may be retained by the mechanical bias imparted through the anchoring to the mitral valve annulus, or using techniques described elsewhere herein. Thecontrol wire300 is thereafter detached from the implant, as illustrated inFIG. 47E.
• Any of a variety of the implants of the present invention may alternatively be introduced across the ventricle, such as in a transapical approach. The retrograde approach to the mitral valve will necessitate certain modifications to both the implant and the deployment system, as will be appreciated by those of skill in the art in view of the disclosure herein.
• For example, a transventricle approach is illustrated inFIGS. 48A through 48D. Adeployment catheter320 is introduced into the ventricle, and retrograde through the mitral valve to position thedistal opening208 within the atrium. An implant is carried within thedeployment catheter320, as has been described elsewhere herein. In general, the implant comprises afirst leaflet support292 and asecond leaflet support294 separated by a flexible zone or pivot point.
• In the retrograde implementation of the invention, the first and second leaflet supports are flexible or pivotable with respect to the longitudinal axis of thecontrol wire300, such that they may be moved between a first configuration in which there are substantially parallel with the axis of thecontrol wire300, and a second position, as illustrated inFIGS. 48A through 48D, in which they are inclined radially outwardly from the longitudinal axis of thecontrol wire300 in the device proximal direction. The implant may thus reside within thedeployment catheter320 when thefirst leaflet support292 andsecond leaflet support294 are in the first, reduced crossing profile configuration, with each of the tissue anchors314 and316 pointing in a device proximal direction. In this embodiment, thetissue anchor314 may be permanently affixed to or integral with thefirst leaflet support292 and thesecond anchor316 may be similarly carried by thesecond leaflet support294.
• Once the distal end of thedeployment catheter320 has been positioned within the atrium, thecontrol wire300 may be distally advanced to advance theanchors314 and316 beyond thedistal opening208. This releases the implant and allows the angle between the first and second leaflet supports to be increased, so that the tissue anchors314 and316 may be aimed at the desired tissue anchor target sites. Proximal retraction on thecontrol wire300 may be utilized to seat the tissue anchors within the target tissue, as illustrated inFIG. 48B.
• Further proximal traction on thecontrol wire300 may be utilized to invert the implant into the configuration illustrated inFIG. 48C. At that point, thecontrol wire300 may be severed from the implant as has been discussed elsewhere herein. Alternatively, thedeployment catheter320 may be proximally retracted leaving thecontrol wire300 secured to the implant, and a second portion of the control wire may be secured to atissue anchor322 within or on the epicardial surface of the ventricle.Anchor322 may comprise any of a variety of structures, such as a pledget, button, or other structure that provides a footprint against the epicardial surface to resist retraction of thecontrol wire300 into the ventricle. Thecontrol wire300 may thereafter be severed proximally of its securement to theanchor322, leaving thecontrol wire300 andanchor322 in position to span the ventricle and retain the configuration of the implant as illustrated inFIG. 48D.
• In all the foregoing embodiments, the final configuration of the implant within the mitral valve is illustrated in a highly schematic form, and the angle and degree of inclination into the direction of the ventricle may be significantly greater than that illustrated herein depending upon the desired clinical performance. The transvalvular band inclination can be highly advantageous in some embodiments in providing clinical benefit as it facilitates “physiologic coaptation” in a preferred manner as its surface mimics the three dimensional feature created by the leaflets as they would have coapted in a healthy native valve.
• Referring toFIGS. 49A through 49H, there is illustrated a transapical approach to the mitral valve, and deployment of a transvalvular band in accordance with the present invention. As illustrated inFIG. 49A, adeployment catheter320 has been introduced such as via thoracotomy, and advanced retrograde through the mitral valve. Atransvalvular band324 has been deployed distally from thecatheter320, and is illustrated inFIG. 49A in an expanded configuration within the left atrium. Expansion of thetransvalvular band324 from a reduced cross-sectional profile for positioning within thecatheter320 to the enlarged cross-sectional profile illustrated inFIG. 49A may be accomplished either under mechanical force, such as by dilatation of an inflatable balloon or other mechanical mechanism. Preferably, however,transvalvular band324 is self-expandable so that it converts from the reduced profile to the enlarged profile automatically upon deployment from the distal end of thecatheter320.
• In the illustrated embodiment, thetransvalvular band324 comprises an arcuate central portion325, which is convex in the direction of the ventricle. SeeFIGS. 49A and 49B. Thetransvalvular band324 is provided with afirst attachment structure326 and asecond attachment structure328.Attachment structures326 and328 may comprise any of a variety of structures disclosed herein, such as tissue anchors, including hooks or barbs. In one implementation of the invention, thefirst attachment structure326, andsecond attachment structure328 each comprise a target for receiving an anchor as will be disclosed below. Suitable targets for the present purpose include woven or non-woven fabrics, polymers, or other materials or constructions which permit a needle or sharpened anchor to penetrate therethrough, as will be discussed. In one implementation of the invention, each of the attachment structures comprises a Dacron mesh, having a frame for supporting the mesh and securing the mesh to thetransvalvular band324.
• Referring toFIG. 49B, there is illustrated a perspective view of thetransvalvular band324 illustrated inFIG. 49A. Thetransvalvular band324 comprises a central section325, convex in the direction of the ventricle for affecting leaflet closure as has been described herein. Central section325 is formed by a frame327, which comprises at least onestrut329 extending between thefirst attachment structure326 andsecond attachment structure328. In the illustrated embodiment, three struts extend generally parallel to each other, defining at least two elongate openings therebetween. One or two or four or moretransverse elements331 may be provided, such as to enhance structural integrity of the construct. At least afirst control wire300 and, optionally a second or third orfourth control wire300 is releasably attached to thetransvalvular band324, to enable manipulation of the band into position as shown inFIG. 49C.Control wire300 is releasably connected to thetransvalvular band324 at aconnection point301. The connection atpoint301 may be established by threadable engagement, an electrolytically detachable link or weld, or other detachment mechanism. Electrolytically detachable deployment systems are know, among other places, in the neurovascular embolic coil and stent arts, and suitable systems are disclosed in U.S. Pat. Nos. 5,976,131 to Guglielmi, et al.; 6,168,618 to Frantzen; and 6,468,266 to Bashiri, et al., the disclosures of which are hereby incorporated in their entireties herein by reference
• Thefirst attachment structure326 comprises a support333 carried by the frame327. In the illustrated embodiment, support333 comprises an enclosed loop, having a central opening filled or covered by amesh337. The support333 may alternatively comprise any of a variety of structures, such as a single linear element, sinusoidal or zigzag pattern, depending upon the desired performance. In the illustrated embodiment, the support333 is conveniently provided in the form of a loop, to facilitateholding mesh337 in a generally planar configuration, and support the mesh so that it may be punctured by an anchor, suture or other retention structure. Asecond support335 is similarly provided with amesh337, to facilitate attachment. Themesh337 may conveniently be a layer or pad of Dacron or other material, such as an integration of a silicone core with a Dacron jacket, which facilitates both piercing by an attachment structure, as well as tissue in-growth for long term retention. The first support333 andsecond support335 may comprise a radio opaque material, or be provided with radio opaque markers to enable aiming the anchor deployment system into themesh337 under fluoroscopic visualization.
• Once thetransvalvular band324 has been brought into the position illustrated inFIG. 49C, thefirst attachment structure326 andsecond attachment structure328 may be secured to the adjacent tissue using any of a variety of clips, staples, barbs, sutures, or other structure which may be conveniently pierced through themesh337 and/or looped around the first andsecond supports333,335. The retention element may be approached from either the side of the left atrium, the ventricle, or epicardially, such as by way of a minimally invasive puncture on the chest wall. In the implementation of the method described below, the example of advancing the retention elements from the left ventricle will be described.
• Referring toFIG. 49C, proximal traction on thecatheter320 and on thecontrol wire300, pulls thetransvalvular band324 snuggly against the left atrial side of the mitral valve, such that thefirst attachment structure326 andsecond attachment structure328 are seated against the valve annulus.
• Referring toFIG. 49D, afirst anchor guide330 and asecond anchor guide332 have been distally advanced from the distal end of thecatheter320. Anchor guides330 and332 may be alternatively associated with or carried by thecatheter320 in a variety of ways. For example, the first and second anchor guides330 and332, may be pivotably carried by thecatheter320, such that they may be inclined radially outwardly from the longitudinal axis of the catheter in the distal direction.
• In the illustrated embodiment, the first and second anchor guides comprise a wire or tube for directing an anchor as will be discussed. The wire or tube of the anchor guide may comprise any of a variety of materials, such as nickel titanium alloys (e.g. nitinol) which may be preset to assume a position similar to that illustrated inFIG. 49D upon distal advance from thecatheter320. The first and second anchor guides may be provided with radio-opaque markers, or may be constructed from a radio-opaque material, to permit fluoroscopic guidance. In the illustrated embodiment, the first and second anchor guides are in the form of tubes, for axially slidably receiving a tissue anchor and tissue anchor deployment structures therein.
• Referring toFIG. 49E, a retention element in the form of afirst anchor334 is illustrated as having been distally advanced from thefirst anchor guide330, through the tissue in the vicinity of the mitral valve annulus, and through thefirst attachment structure326. Penetration of thefirst anchor334 through thefirst attachment structure326 may be accomplished while providing proximal traction on thecontrol wire300.
• Thefirst anchor334 is provided with at least one and preferably two or four or moretransverse elements336 to resist proximal retraction of thefirst anchor334 back through the opening formed in thefirst attachment structure326. The transverse element orsurface336 may be provided on any of a variety of structures, such as an umbrella-type structure, t-tag, barbs, or other anchoring configuration which can pass in a first direction through an opening formed in thefirst attachment structure326, but resist retraction in a second, opposite direction, back through thefirst attachment structure326.
• Thetransverse element336 is carried by afilament338, which extends through the adjacent myocardial tissue.Filament338 may comprise any of a variety of materials, such as a monofilament or multi-filament structure made from polypropylene, any of a variety of other known suture materials such as polyethylene, or metals such as stainless steel, nitinol, and others known in the art. Thefilament338 may be a mono-filament structure or a multi-filament structure which may be braided or woven, depending upon the desired clinical performance. At least a second,similar anchor340 is introduced on the opposing side of the mitral valve.
• Referring toFIG. 49F, a secondtransverse element342 is shown secured to or carried by the ventricular end of thefilament338, to provide a secure anchoring through the tissue wall for the transvalvular band. A similar structure is provided on the opposing side of the mitral valve. Although only a first and second anchoring systems has been described above, additional anchoring systems, such as a total of four or six or eight or more, typically in even numbers to produce bilateral symmetry, may be used. The number and configuration of tissue anchors will depend upon the configuration of the transvalvular band, as will be apparent to those of skill in the art in view of the disclosure herein.
• As shown inFIG. 49F, the anchors have been fully deployed and thefirst anchor guide330 andsecond anchor guide332 have been proximally retracted into thecatheter320.
• Referring toFIG. 49G, thecontrol wire300 may thereafter be detached from the transvalvular band and removed. Detachment ofcontrol wire300 may be accomplished in any of a variety of ways, as has been described elsewhere herein.
• Alternatively, thecontrol wire300 may be left in place as is illustrated inFIG. 49H.Control wire300 is secured to anepicardial anchor322, to provide a transventricular truss, as has been described.
• Referring toFIGS. 50A and 50B, there is illustrated a side elevational schematic view of the distal end of adeployment catheter360 which may be adapted for use in either the transapical delivery ofFIGS. 49A-49H, or any other delivery mode described herein. In the illustrated embodiment, thedeployment catheter360 includes an elongate tubular body having acentral lumen362, opening at adistal end364. Carried within thecentral lumen362 is atransvalvular band366, in a rolled-up configuration.Transvalvular band366 is maintained in a rolled-up configuration by the constraint imposed by thedeployment catheter360. However, upon distal advance of thepush element368 to deploy thetransvalvular band366 beyond thedistal end364, as illustrated inFIG. 50B, thetransvalvular band366 unrolls under its natural bias into a predetermined configuration for implantation across the mitral valve.
• One configuration for the transvalvular band is shown rolled out in plan view inFIG. 51A. However, any of a variety of alternative transvalvular band configurations disclosed herein can be utilized with the catheter ofFIGS. 50A and 50B.
• Referring toFIG. 51A, there is illustrated atransvalvular band366 having acentral portion368 for spanning the coaptive edges of the mitral valve. Afirst attachment zone370 and asecond attachment zone372 are provided on opposing ends of thecentral portion368.
• The central portion comprises at least afirst strut374 for spanning the mitral valve as has been discussed. In the illustrated embodiment, asecond strut376 and athird strut378 are provided, spaced apart to increase the width of the contact footprint with the valve leaflet but permit blood flow therethrough. A first end of each of thestruts374,376, and378 are connected at thefirst attachment zone370, and the second ends of the three struts are connected at thesecond attachment zone372.
• The first and second attachment zones may be provided with a reinforcingelement382, to facilitate long term attachment.Apertures380 are illustrated, which may be provided to allow manual suturing when thetransvalvular band366 is intended for use in an open surgical procedure. Alternatively,apertures380 may be configured for attachment using an anchor deployment catheter when intended for use in a translumenal or transapical deployment. Each of the first, second and third ribs may be provided with a central core, such as a nitinol or stainless steel wire or ribbon, and an outer coating such as a polycarbonate urethane with or without copolymers like silicone, silicone coating, or a fabric such as PET, ePTFE, polyethylene, or a hybrid of, for example, the aforementioned materials impregnated silicone coating, to reduce the risk of abrasion of the mitral valve leaflets A close-up view of circled zone51D ofFIG. 51A is illustrated inFIG. 51D.
• FIG. 51D illustrates one embodiment of a fatigue-resistant terminal portion of a proximal and/or distal end of one, two, or more of thestruts374,376,378 illustrated inFIG. 51D. The terminal portion51D may have anon-linear portion378′ and a head portion379. The non-linear portion could be a coil with a helical, zig-zag, or any other generally non-linear shape to advantageously provide increased fatigue resistance for the struts. In some embodiments, at least a portion of the terminal portion51D is embedded in an elastomer such as silicone, polycarbonate, urethane, or the like to further improve fatigue tolerance. In some embodiments, the terminal portion51D may have a straight-line length that is less than 20%, 15%, 10%, 5%, or less of the strut. In some embodiments, the terminal portion51D may have a straight-line length that is at least about 5%, 10%, 15%, 20%, 25%, or more of the length of the strut, or could even cover the entire length of one, two, ormore struts374,376,378 fromfirst attachment zone370 to second attachment zone372 (e.g., a strut without a linear portion). Head portion379 is operably connected tonon-linear portion378′ and the portions may be integrally formed. The head portion379 could be spherical, ovoid, square, rectangular, triangular, or a variety of other shapes. Head portion379 is in turn operably connected tofirst attachment zone370 and/orsecond attachment zone372. In some embodiments, the head portion379 is not attached to an attachment zone but rather terminates as a free end of one or more of thestruts374,376,378.
• FIG. 51B is a side elevational view of thetransvalvular band366 ofFIG. 51A, shown in a flat configuration. However, as has been discussed elsewhere herein, the transvalvular band will typically be provided with a curvature such that it advances the mitral valve leaflets in the direction of the ventricle and provides for physiologic coaptation.
• FIG. 51C illustrates a perspective view of atransvalvular band366 in a rolled-up configuration for delivery, similar to that illustrated inFIG. 50B. The band can be rolled in a variety of ways, such as capturing theband366 at or near the center (near363) and rolling it such that both ends are drawn inward as shown. In some embodiments, the band could be rolled up like a scroll, or folded into a “V”, “W”, or a variety of other shapes. In some embodiments, at least a portion of theband366 resides within one or more slots363 or movable jaw-like elements on the distal end363 of amandrel367 or other elongate body within a delivery catheter. Actuation of the jaw-like elements to release theband366, distal movement of a pusher tube, retraction of themandrel367 relative to another catheter, or other mechanism can be employed to deploy theband366. In some embodiments, turning the mandrel a desired distance, such as about 90 degrees, can help facilitate unfurling of theband366 for deployment.
• Referring toFIGS. 52A-52C, there is illustrated a transvalvular band in accordance with the present invention having a tissue attachment system which may be adapted for either percutaneous or open surgical use. The transvalvular band comprises acentral zone368 carrying afirst attachment zone370 and asecond attachment zone372 as has been described.
• Atissue anchor390, such as a “t-tag” anchor includes atransverse element392 and an elongateflexible suture394. As used herein, the term “suture” is not limited to its normal definition, but also includes any of a wide variety of elongate flexible filaments, including polymeric, metal, combinations of both as well as monofilament and multifilament structures. Multifilament structures may be braided, woven, or otherwise configured, depending upon the desired performance.
• Thesuture394 is illustrated to extend through afirst guide396 in thesecond attachment zone372. For simplicity, only a single anchoring system will be disclosed herein. However, it should be appreciated that the anchoring system may be utilized on both ends of thecentral zone368, and more than one, such as two or three or more, anchors390 may be utilized on each attachment zone.
• Thesuture394 is illustrated as extending throughfirst guide396, and then through alock398 which will be described below. Thefree end402 of thesuture394 is further advanced through asecond guide400. Depending upon the intended use of the system, thefree end402 may extend proximally throughout the length of the deployment catheter, where it may be manipulated such as by proximal traction in order to tighten thesecond attachment zone372 with respect to thetransverse element392. Thereafter, thefree end402 may be severed in the vicinity of thesecond attachment zone372 or elsewhere.
• Referring toFIG. 52C, details of thelock398 may be seen. In general, thelock398 includes anaperture404 through which thesuture394 may extend. Anengaging element406 is exposed to the interior of the aperture, for permitting the suture to advance in a first direction through theaperture404 but resist movement of thesuture394 in an opposite direction through theaperture404. In the illustrated embodiment, the engagingelement406 is a sharpened point or spike configured to mechanically pierce or engage thesuture394.
• The foregoing structure permits thefree end402 to be proximally withdrawn away from thesecond attachment zone372 in a manner that draws thetransverse element392 closer to thesecond attachment zone372. However, traction on thetransverse element392 causes thesuture394 to engage theengaging element406, and prevents thetransverse element392 from pulling away from thesecond attachment zone372.
• Referring toFIG. 52D, illustrated is asuture394 which can be looped through one, two, or moretransverse elements392 of anchors. Thesuture394 looped through the anchor can function as a pulley, where appropriate traction on thesuture394 can tighten the anchors into place. Having a plurality of anchors as shown connected on one loop, such as, for example, 2, 3, 4, 5, or more anchors, can advantageously allow one cinching maneuver to tighten all of the anchors at once.
• Referring back toFIG. 52A, ananchor deployment tool408 is illustrated.Deployment tool408 may comprise an elongate flexible wire having aproximal end410 and adistal end412. Thedeployment tool408 may extend throughout the length of a percutaneous translumenal catheter, with theproximal end410 exposed or attached to a control to allow axial reciprocal movement of thedeployment tool408. Thedistal end412 is releasably positioned within anaperture414 on a first end of thetransverse element392. A second end of thetransverse element392 is provided with a sharpenedpoint416.
• In use, distal axial advance of thedeployment tool408 is utilized to drive thetransverse element392 into a target tissue, to a desired depth. Once the desired depth has been achieved, proximal retraction on thedeployment tool408 proximally retracts thedistal end412 out of theaperture414, allowing removal of thedeployment tool408 but leaving thetransverse element392 behind within the target tissue. Proximal traction on thefree end402 of thesuture394 enables tightening of the transvalvular band with respect to thetransverse element392. Once a desired level of tightening has been achieved, releasing thefree end402 allows engagingelement406 to lock thesuture394 against further release, thereby holding the transvalvular band into position.
• Although thelock398 is illustrated as an enclosed aperture, alternative lock embodiments may involve access from a lateral edge of the implant. This permits side-loading of the suture into the lock, which may in some instances be desired over an enclosed aperture which requires end loading of the suture through the aperture. A variety of alternative side-loading lock configurations is illustrated inFIG. 53.
• Referring toFIG. 54, there is illustrated a perspective view of an alternate transvalvular band in accordance with the present invention. In this embodiment, thecentral section368 is provided with an asymmetrical curvature, to provide asymmetrical support to the mitral valve leaflets. Along the width or central portion of the transvalvular band, this provides a contour mimicking the three-dimensional shape of the coapted mitral valve in a healthy native valve, and provides a physiologic analog thereby promoting correct anatomy during coaptation.
• FIGS. 55 and 56 illustrate alternative transvalvular bands in accordance with the present invention. In these embodiments, the attachment zones are provided with tissue anchors configured to pierce the tissue of the valve annulus. In general, the tissue anchors each comprise a pointed end, for penetrating tissue and a retention structure for resisting removal of the tissue anchor from the tissue. The retention element inFIG. 55 is in the form of a first or second barb or shoulder, as will be understood by those skilled in the art. The retention feature of the transvalvular band illustrated inFIG. 56 comprises an arcuate configuration for the tissue-piercing structure. Compression from the closure of the valve leaflets against the convex side of the central zone will tend to impart a circumferential force on the tissue anchors, advancing the distal point further in the direction of its own arcuate path. This construction tends to allow the natural forces of closure of the mitral valve to increase the retention of the tissue anchor within the adjacent tissue. In some embodiments, the barbs can be used as a primary anchor that can be crimped or otherwise secured in place. In other embodiment, the barbs could act as positioning features, to temporarily hold the band in place while verifying the position. The band could then be anchored in a secondary step, such as using a crimp, staple, suture, or other anchor as described herein. In some embodiments, the barbs can be self-locking upon penetration through tissue.
• In some embodiments, disclosed is a transvalvular band that provides resistance to coaptation in the same manner as the chordae provides resistance to coaptation in a continuously nonlinear fashion, like a viscoelastic response. This band could have a configuration such as described and illustrated above, and could have material properties or additional features to provide non-linear resistance to coaptation. Such embodiments could retain a curvature mimicking the natural three dimensional surface of the coapted mitral valve yet could displace in the retrograde direction up to the anatomically correct plane of coaption when appropriate. The direction of displacement, for example, with respect to the mitral valve is better described in the atrial direction during systole to provide a cushioned impact for the valve leaflets as opposed to the leaflets striking a ridged implant structure and remodeling in a potentially deleterious fashion such as fibrosis or thinning around impact edges.FIG. 56A is reproduced from Nielsen et al, Circulation 2003; 108:486-491,Influence of Anterior Mitral Leaflet Second-Order Chordae Tendineae on Left Ventricular Systolic Function, which is hereby incorporated by reference in its entirety, illustrating a bilinear relationship between LV pressure and chordal tension during isovolumic contraction, a decrease in chordal tension despite high LV pressure during ejection, and an almost linear decline during isovolumic relaxation.FIG. 56B is reproduced from Nielsen et al, J Thorac Cardiovasc Surg 2005; 129:525-31,Imbalanced chordal force distribution causes acute ischemic mitral regurgitation: Mechanistic insights from chordae tendineae force measurements in pigs, which is incorporated by reference in its entirety. These figures demonstrate that chordae force with respect to time increases and then decays in a non-linear manner during systole. A band mimicking this performance could benefit the valvular surface as it returns its coaptive forces to a near normal state. In some embodiments, a band could cushion or physiologically reduce or prevent physical stress caused by repetitive contact with the coaptive leaflet surfaces. The band could accomplish this by virtue of construction such as chambered struts that may or may not be filled with a media such as a fluid. These chambers would be enclosed and impermeable or substantially impermeable to blood or blood component penetration within a lifetime. Another method of cushioned coaption would be a device that allows some flexing during coaption. This flexibility could be designed based upon strut material, thickness, width, inferior and superior cross-section such as a ripple, or encapsulation material such as an elastomer or elastomeric foam. The foam material could be sealed by an exterior polymer of equal overall flexibility. Additional embodiments would be coils (such as illustrated inFIG. 51D above) or coils within coils to produce unique nonlinear displacement signatures or tubes such as Nitinol laser cut tubes that could optionally be filled with a polymer. Yet another embodiment would include struts that loop towards the ventricle crossing itself. This loop would also create this nonlinear resistance to coaption by its spring force. In other embodiments, the band can proceed down to the chordae and devices can be adapted to shorten or augment the chordae to achieve natural physiology. Devices of this manner can be, for example, crimped bands with elastomer bodies between the crimped bands. The elastomeric bodies would replicate the deficient portion of the chordae to mimic the correct force curve during coaptation. This may provide enough benefit in some grades of the disease so as to provide palliative care or resolve it.
• Any of a wide variety of specific tissue anchor constructions may be utilized in combination with the transvalvular band of the present invention. In addition, a variety of features have been described as illustrative in connection with a variety of implementations of the invention. Any of the features described above, may be recombined with any other of the embodiments disclosed herein, without departing from the present invention, as should be apparent to those of skill in the art.
• Referring toFIG. 57, there is illustrated a dilated mitral annulus with restricted posterior leaflet motion due to distortion of the posterior papillary muscles due to enlargement of the left ventricular chamber. This condition occurs in ischemic or dilated cardiomyopathy. The schematically illustrated result is malcoaption of leaflets, causing central mitral regurgitation.
• FIG. 57 schematically illustrates a heart, in which leftventricle400 is separated fromleft atrium402 by amitral valve406. Themitral valve406 comprises an annulus,anterior leaflet406 andposterior leaflet408.Posterior leaflet408 is distorted due to expansion of the ventricular wall pulling the posterior leaflet viamarginal chordae410, which connect to the posteriorpapillary muscle412. Theanterior leaflet406 is properly restrained by the anteriorpapillary muscle414. Also illustrated are theintraventricular septum416,aortic valve418, and theaorta420.
• Referring toFIG. 58, there is illustrated a schematic view of the normal mitral annulus during systole, looking from the left atrium in the direction of the left ventricle.FIG. 59 illustrates a mitral valve in ischemic and dilated cardiomyopathy, in systole, looking from the left atrium in the direction of the left ventricle. The illustration ofFIG. 59 shows central mitral regurgitation in the region of the P2 and P3 scallops of the posterior leaflet.
• Mitral regurgitation is the frequent cause of severe congestive heart failure in many patients with progressive left ventricular chamber enlargement due to primary dilated or ischemic cardiomyopathy. Mechanism of mitral regurgitation is due to mitral annular dilatation casing malcoaptation of the mitral valve leaflets during ventricular systole (FIG. 57,FIG. 59), and distortion of papillary muscles (to which mitral valve leaflets are attached) due to left ventricular chamber enlargement which causes restricted leaflet motion. This process frequently affects the posterior leaflet of mitral valve (FIG. 57,FIG. 59)
• Current surgical treatment consists of mitral annuloplasty and many complex subvalvular procedures i.e. papillary muscle repositioning and cutting only the strut chordae near the base of the leaflet and the left ventricle. These open heart surgical procedures are time consuming, invasive and require cardiopulmonary bypass. They have not yielded satisfactory results because of the progressive enlargement of the left ventricle and further distortion of attached leaflet chordae papillary muscle apparatus. For the same reason transcatheter annuloplasty and edge to edge repair of mitral valve leaflets have not been very successful.
• In accordance with aspects of the present invention described above, there has been provided a simple transvalvular intraannular band device for treating mitral regurgitation due to mitral valve prolapse where there is excessive motion of the valve leaflets above the plane of the annulus. Implantation may be accomplished surgically or transvascularly. But in certain patients, continued enlargement of the left ventricular chamber cooperates with intact chordae to produce or progress regurgitation.
• Thus, in accordance with a further aspect of the present invention, there are provided methods and devices for treatment of ischemic and dilated cardiomyopathy patients with mitral regurgitation. In accordance with the methods, the main marginal chordae of the posterior mitral valve leaflets are cut, preferably in the region of P2 P3 scallops of the valve then the posterior leaflet will be allowed to prolapse into the left atrium above the plane of the mitral annulus (FIG. 61). Then this prolapse will be treated by inserting one of the transvalvular intraannular bands in the mitral annulus (FIG. 62), as has been described elsewhere herein.
• This procedure can be accomplished through a surgically open, minimally invasive approach with a very short operative time. The chordal cutting and the band deployment could be done percutaneously by a transcatheter technique with access via the femoral vein into interatrial septum entering the left atrium and left ventricle (FIGS. 60-61). Alternatively, this could be done from femoral artery approach into the ascending aorta and through the aortic valve for cutting the chordae and deployment of the band. Another access could be through transapical approach from the left ventricular apex (FIG. 62). Any two or all of these percutaneous approaches could be also combined.
• The chordae cutting instruments vary from microscissors, microknife or other sharpened edge based cutting instruments, to cryoablation, ultrasonic, radiofrequency, microwave, laser energies or other cutting techniques known in the art.
• Thus, referring toFIG. 60, atransseptal catheter422 has been placed across theseptum428 between theright atrium426 andleft atrium402, via asuperior vena cava424 access. Adistal end423 of thetransseptal catheter422 is positioned in the vicinity of the mitral valve. A cord cutting instrument430 is advanced through the transseptal catheter and out thedistal end423, to selectively sever one or two or four or more of themarginal chordae410. The cord cutting instrument430 comprises an elongateflexible body432 having a proximal end with a cutter control thereon (not illustrated) and a distal end with atissue cutter434. The control may be varied considerably, depending upon the nature of the cord cutting modality. For example, mechanical knobs, levers and sliders may be utilized to control mechanical cutters such as scissors or knives. Electrical switch, button or knob may be utilized to control other energy based cutting modalities, such as radio frequency, microwave, laser or ultrasound.
• Once sufficient marginal chordae have been severed to release the posterior leaflet from the constraint imposed by the dilated cardiomyopathy, the posterior leaflet is freed to prolapse as illustrated inFIG. 61. However, either prior to severing the marginal chordae or following the severing of the marginal chordae, a mitral valve leaflet support in the form of any of the transvalvular bands disclosed previously herein is positioned across the mitral valve, as schematically illustrated inFIG. 63. The transmitral band (e.g., transvalvular) prevents prolapse of the posterior leaflet into the left atrium, despite the cut marginal chordae, and the cut marginal chordae enables complete coaption of the leaflets shown with no regurgitation into the left atrium during systole.
• Referring toFIG. 62, there is illustrated an alternative access to the mitral valve, via atransapical catheter438. Adistal end439 of thetransapical catheter438 is positioned within the left ventricle. A cord cutting instrument430 is advanced therethrough, such that an elongateflexible body432 carries atissue cutter434 into themarginal chordae410. Any of a variety of tissue cutting tips may be utilized fortissue cutter434 as has been described elsewhere herein. The marginal chordae may be severed via transapical approach either prior to or following implantation of the transvalvular band described elsewhere herein.
• Although the foregoing description has been primarily in the context of severing the marginal chordae to release the posterior leaflet, that is merely an example of the invention which involves manipulating the heart to release the leaflet from a constraint imposed by a heart condition, and then treating the resulting prolapse by implantation of a leaflet support. Manipulation can be any procedure that increases the range of travel of the constrained leaflet, with complete severing of at least one marginal chordae being a convenient technique. Manipulations that stretch the marginal chordae, or which sever or stretch the corresponding papillary muscle may alternatively be used. A portion or all of the severed chordae or papillary muscle may be removed, or left in situ as illustrated inFIGS. 61 and 63.
• While the foregoing detailed description has set forth several exemplary embodiments of the apparatus and methods of the present invention, it should be understood that the above description is illustrative only and is not limiting of the disclosed invention. It will be appreciated that the specific dimensions and configurations disclosed can differ from those described above, and that the methods described can be used within any biological conduit within the body.

Claims (15)

1. A method of treating mitral valve prolapse, the method comprising:

implanting in the mitral annulus an intraannular band comprising an elongate and arcuate body having a first end, a first anchoring portion located proximate the first end, a second end, a second anchoring portion located proximate the second end, and a central portion, the central portion displaced out of the plane containing the first end and the second end;

attaching the first anchoring portion to one portion of the mitral annulus;

attaching the second anchoring portion to another portion of the mitral annulus such that the intraannular band extends transversely across a coaptive edge formed by the closure of the mitral valve leaflets and the central portion is displaced towards the left ventricle relative to the first anchoring portion and the second anchoring portion; and

severing at least one marginal chordae.

2. A method of treating a mitral valve, comprising the steps of:

providing a transvalvular band having a convex side and a projection extending from the convex side;

securing the band to a valve annulus such that the convex side extends across the plane of the annulus in the direction of the ventricle, and the projection extends in a downstream blood flow direction, so that a first leaflet closes against a first side of the projection and a second leaflet closes against a second side of the projection; and

severing at least one marginal chordae.

3. A method of treating a mitral valve as inclaim 2, wherein the securing step comprises securing a first end and a second end of the band within the plane of the annulus such that the convex side extends from the plane in the direction of the ventricle to cause early leaflet closure.

4. A method of treating a mitral valve as inclaim 2, further comprising the step of securing a portion of the first and second leaflets to the projection.

5. A method of treating ischemic or dilated cardiomyopathy, comprising the steps of:

providing an intraannular, transvalvular band dimensioned for attachment within the plane of the mitral valve annulus;

attaching the band within the plane of the annulus such that a portion of the band extends into the ventricular side of the plane to support the leaflets and elevate the position of the coaptive edges in the direction of the ventricle during valve closure and

manipulating at least one marginal chordae to permit leaflet coaption.

6. A method as inclaim 5, wherein the elevate the position step comprises elevating the position of the coaptive edges by at least about 4 mm.

7. A method as inclaim 5, wherein the elevate the position step comprises elevating the position of the coaptive edges by an amount within the range of from about 6 mm to about 12 mm.

8. A method as inclaim 5, wherein the manipulating step comprises severing at least one marginal chordae.

9. A method as inclaim 8, comprising severing at least two marginal chordae.

10. A method as inclaim 5, wherein the manipulating step is accomplished prior to the attaching step.

11. A method as inclaim 5, wherein the manipulating step is accomplished following the attaching step.

12. A method as inclaim 5, wherein the manipulating step is accomplished with a sharpened edge.

13. A method as inclaim 5, wherein the manipulating step comprises applying RF energy.

14. A method of treating a patient, comprising the steps of deploying an implant to resist prolapse of a mitral valve leaflet into the left atrium, and cutting at least one marginal chordae.

15. A system for treating a patient, comprising at least one catheter for accessing the heart; an implant for positioning in contact with at least one mitral valve leaflet, and a marginal chordae cutter.

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