Devices and methods for heart valve treatment

Devices and methods for improving the function of a valve (e.g., mitral valve) by positioning an implantable device outside and adjacent the heart wall such that the device alters the shape of the heart wall acting on the valve. The implantable device may alter the shape of the heart wall acting on the valve by applying an inward force and/or by circumferential shortening (cinching). The shape change of the heart wall acting on the valve is sufficient to change the function of the valve, and may increase coaptation of the leaflets, for example, to reduce regurgitation.

FIELD OF THE INVENTION

The present invention relates to devices and associated methods for treating and improving the performance of dysfunctional heart valves. More particularly, the invention relates to devices and methods that passively assist to reshape a dysfunctional heart valve to improve its performance.

BACKGROUND OF THE INVENTION

Various etiologies may result in heart valve insufficiency depending upon both the particular valve as well as the underlying disease state of the patient. For instance, a congenital defect may be present resulting in poor coaptation of the valve leaflets, such as in the case of a monocusp aortic valve, for example. Valve insufficiency also may result from an infection, such as rheumatic fever, for example, which may cause a degradation of the valve leaflets. Functional regurgitation also may be present. In such cases, the valve components may be normal pathologically, yet may be unable to function properly due to changes in the surrounding environment. Examples of such changes include geometric alterations of one or more heart chambers and/or decreases in myocardial contractility. In any case, the resultant volume overload that exists as a result of an insufficient valve may increase chamber wall stress. Such an increase in stress may eventually result in a dilatory process that further exacerbates valve dysfunction and degrades cardiac efficiency.

Mitral valve regurgitation often may be driven by the functional changes described above. Alterations in the geometric relationship between valvular components may occur for numerous reasons, including events ranging from focal myocardial infarction to global ischemia of the myocardial tissue. Idiopathic dilated cardiomyopathy also may drive the evolution of functional mitral regurgitation. These disease states often lead to dilatation of the left ventricle. Such dilatation may cause papillary muscle displacement and/or dilatation of the valve annulus. As the papillary muscles move away from the valve annulus, the chordae connecting the muscles to the leaflets may become tethered. Such tethering may restrict the leaflets from closing together, either symmetrically or asymmetrically, depending on the relative degree of displacement between the papillary muscles. Moreover, as the annulus dilates in response to chamber enlargement and increased wall stress, increases in annular area and changes in annular shape may increase the degree of valve insufficiency. Annular dilatation is typically concentrated on the posterior aspect, since this aspect is directly associated with the dilating left ventricular free wall and not directly attached to the fibrous skeleton of the heart. Annular dilatation also may result in a flattening of the valve annulus from its normal saddle shape.

Alterations in functional capacity also may cause valve insufficiency. In a normally functioning heart, the mitral valve annulus contracts during systole to assist in leaflet coaptation. Reductions in annular contractility commonly observed in ischemic or idiopathic cardiomyopathy patients therefore hamper the closure of the valve. Further, in a normal heart, the papillary muscles contract during the heart cycle to assist in maintaining proper valve function. Reductions in or failure of the papillary muscle function also may contribute to valve regurgitation. This may be caused by infarction at or near the papillary muscle, ischemia, or other causes, such as idiopathic dilated cardiomyopathy, for example.

The degree of valve regurgitation may vary, especially in the case of functional insufficiency. In earlier stages of the disease, the valve may be able to compensate for geometric and/or functional changes in a resting state. However, under higher loading resulting from an increase in output requirement, the valve may become incompetent. Such incompetence may only appear during intense exercise, or alternatively may be induced by far less of an exertion, such as walking up a flight of stairs, for example.

Conventional techniques for managing mitral valve dysfunction include either surgical repair or replacement of the valve or medical management of the patient. Medical management typically applies only to early stages of mitral valve dysfunction, during which levels of regurgitation are relatively low. Such medical management tends to focus on volume reductions, such as diuresis, for example, or afterload reducers, such as vasodilators, for example.

Early attempts to surgically treat mitral valve dysfunction focused on replacement technologies. In many of these cases, the importance of preserving the native subvalvular apparatus was not fully appreciated and many patients often acquired ventricular dysfunction or failure following the surgery. Though later experience was more successful, significant limitations to valve replacement still exist. For instance, in the case of mechanical prostheses, lifelong therapy with powerful anticoagulants may be required to mitigate the thromboembolic potential of these devices. In the case of biologically derived devices, in particular those used as mitral valve replacements, the long-term durability may be limited. Mineralization induced valve failure is common within ten years, even in younger patients. Thus, the use of such devices in younger patient groups is impractical.

Another commonly employed repair technique involves the use of annuloplasty rings. These rings originally were used to stabilize a complex valve repair. Now, they are more often used alone to improve mitral valve function. An annuloplasty ring has a diameter that is less than the diameter of the enlarged valve annulus. The ring is placed in the valve annulus and the tissue of the annulus sewn or otherwise secured to the ring. This causes a reduction in the annular circumference and an increase in the leaflet coaptation area. Such rings, however, generally flatten the natural saddle shape of the valve and hinder the natural contractility of the valve annulus. This may be true even when the rings have relatively high flexibility.

To further reduce the limitations of the therapies described above, purely surgical techniques for treating valve dysfunction have evolved. Among these surgical techniques is the Alfiere stitch or so-called bowtie repair. In this surgery, a suture is placed substantially centrally across the valve orifice joining the posterior and anterior leaflets to create leaflet apposition. Another surgical technique includes plication of the posterior annular space to reduce the cross-sectional area of the valve annulus. A limitation of each of these techniques is that they typically require opening the heart to gain direct access to the valve and the valve annulus. This generally necessitates the use of cardiopulmonary bypass, which may introduce additional morbidity and mortality to the surgical procedures. Additionally, for each of these procedures, it is very difficult to evaluate the efficacy of the repair prior to the conclusion of the operation.

Due to these drawbacks, devising effective techniques that could improve valve function without the need for cardiopulmonary bypass and without requiring major remodeling of the valve may be advantageous. In particular, passive techniques to change the shape of the heart chamber and/or associated valve and reduce regurgitation while maintaining substantially normal leaflet motion may be desirable. Further, advantages may be obtained by a technique that reduces the overall time a patient is in surgery and under the influence of anesthesia. It also may be desirable to provide a technique for treating valve insufficiency that reduces the risk of bleeding associated with anticoagulation requirements of cardiopulmonary bypass. In addition, a technique that can be employed on a beating heart would allow the practitioner an opportunity to assess the efficacy of the treatment and potentially address any inadequacies without the need for additional bypass support.

SUMMARY OF THE INVENTION

To address these needs, the present invention provides, in exemplary non-limiting embodiments, devices and methods for improving the function of a valve (e.g., mitral valve) by positioning an implantable device outside and adjacent the heart wall such that the device alters the shape of the heart wall acting on the valve. The implantable device may include two anchor ends with a interconnecting member connected therebetween. The anchor ends and the interconnecting member may be positioned on the outside of the heart. Optionally, a protrusion may be connected to the interconnecting member between the anchor ends. The anchor ends may be connected to the heart wall around the dysfunctional valve, and the interconnecting member may be tightened or cinched therebetween. Because the heart wall is generally curved, the act of cinching the interconnecting member between the attached anchor ends may cause the interconnecting member to apply an inward force against the heart wall acting on the dysfunctional valve, and/or may shorten the distance between the anchor ends and thus deform the heart wall inward to act on the dysfunctional valve. The inward force may act on any one of or any combination of valve structures (e.g., valve annulus, papillary muscles, etc.) and/or adjacent anatomical coronary structures. If a protrusion is utilized, it may be used to apply and focus additional force against the heart wall.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The various aspects of the devices and methods described herein generally pertain to devices and methods for treating heart conditions, including, for example, dilatation, valve incompetencies, including mitral valve leakage, and other similar heart failure conditions. Each disclosed device may operate passively in that, once placed on the heart, it does not require an active stimulus, either mechanical, electrical, hydraulic, pneumatic, or otherwise, to function. Implanting one or more of the devices operates to assist in the apposition of heart valve leaflets to improve valve function.

In addition, these devices may either be placed in conjunction with other devices that, or may themselves function to, alter the shape or geometry of the heart, locally and/or globally, and thereby further increase the heart's efficiency. That is, the heart experiences an increased pumping efficiency through an alteration in its shape or geometry and concomitant reduction in stress on the heart walls, and through an improvement in valve function.

However, the devices disclosed herein for improving valve function can be “stand-alone” devices, that is, they do not necessarily have to be used in conjunction with additional devices for changing the shape of a heart chamber or otherwise reducing heart wall stress. It also is contemplated that a device for improving valve function may be placed relative to the heart without altering the shape of the chamber, and only altering the shape of the valve itself. In other words, the devices and methods described herein involve geometric reshaping of portions of the heart and treating valve incompetencies.

The devices and methods described herein offer numerous advantages over the existing treatments for various heart conditions, including valve incompetencies. The devices are relatively easy to manufacture and use, and the transluminal, transthoracic, and surgical techniques and tools for implanting the devices do not require the invasive procedures of current surgical techniques. For instance, these techniques do not require removing portions of the heart tissue, nor do they necessarily require opening the heart chamber or stopping the heart during operation. For these reasons, the techniques for implanting the devices disclosed herein also are less risky to the patient than other techniques. The less invasive nature of these techniques and tools may also allow for earlier intervention in patients with heart failure and/or valve incompetencies.

Although the methods and devices are discussed hereinafter in connection with their use for the mitral valve of the heart, these methods and devices may be used for other valves of the heart for similar purposes. One of ordinary skill in the art would understand that the use of the devices and methods described herein also could be employed for other valves of the heart. The mitral valve has been selected for illustrative purposes because a large number of the disorders occur in connection with the mitral valve.

The devices and methods described herein are discussed herein with reference to the human heart H, but may be equally applied to other animal hearts not specifically mentioned herein. For purposes of discussion and illustration, several anatomical features may be labeled as follows: left ventricle LV; right ventricle RV; left atrium LA; ventricular septum VS; right ventricular free wall RVFW; left ventricular free wall LVFW; atrioventricular groove AVG; mitral valve MV; tricuspid valve TV; aortic valve AV; pulmonary valve PV; papillary muscle PM; chordae tendeneae CT (or simply chordae); anterior leaflet AL; posterior leaflet PL; coaptation line CL; annulus AN; ascending aorta AA; thoracic aorta TA; azygos vein AZV; coronary sinus CS; cardiac vein CV; right coronary artery RCA; left anterior descending artery LAD; obtuse marginal artery OM; circumflex artery CFX; left lung LL; right lung RL; dermal layer DL; sternum ST; xiphoid XPH; diaphragm DPH; and vertebrae VRT.

General Description of Exemplary Implant Devices

With reference toFIGS. 1A and 1B, a generic implantable device10is shown schematically. The implantable device10may generally include two or more anchor ends12/14with a interconnecting member16connected therebetween. The anchor ends12/14may be configured to permanently or releasably attach to the outside of the heart wall. The interconnecting member16may be selectively tightened or loosened to correspondingly affect the tension between the anchor ends12/14. A protrusion18may be connected to the interconnecting member16between the anchor ends12/14. Alternatively, as shown inFIGS. 1C and 1D, the implantable device10may utilize anchor ends12/14and interconnecting member16alone, without the use of a protrusion18. With or without protrusion18, the interconnecting member may be generally flexible to conform to the outer surface of the heart. Protrusion18may alternatively be referred to as a space filling member or a focal member. Interconnecting member16may alternatively be referred to as an elongate member or as a tension member.

The position of the protrusion18may be adjusted relative to the anchor ends12/14. To accommodate such adjustment, the interconnecting member16may be fixedly connected to one or both of the anchor ends12/14and adjustably connected to the protrusion18. Alternatively, the interconnecting member16may be fixedly connected to the protrusion18and adjustably connected to one or both of the anchor ends12/14. In both instances, the length of the interconnecting member16between the protrusion18and the anchor ends12/14may be adjusted to change the position of the protrusion18relative to the anchor ends12/14.

The anchors12/14serve to secure the ends of the interconnecting member16to the heart wall. The anchors12/14may comprise vacuum cups with tissue piercing pins for securement as described in more detail with reference toFIGS. 5A-5D. The anchors12/14may be remotely activated as described with reference toFIGS. 6 and 7. The anchors12/14may selectively connect to some tissue (e.g., epicardium, myocardium) while remaining free of other tissue (e.g. pericardium). Various alternative anchor embodiments are envisioned, such as tines, screws, sutures, adhesives, etc., and/or a tissue in-growth promoting material (e.g., Dacron fabric). For example, the anchors12/14may comprise tines that extend through the epicardium and into the myocardium, and optionally extend through the endocardium into a heart chamber. Additional alternative anchor embodiments are described by Vidlund et al., '519.

The interconnecting member16may be fixed or selectively fixed (i.e., adjustable) to each of the anchors12/14and/or the protrusion18as described above. The interconnecting member may be made fixed or adjustable using, for example, a lock pin technique as described in more detail with reference toFIGS. 5A-5D.

As an alternative to interconnecting member16, or in conjunction with interconnecting member16, pericardial tissue may be used to connect the anchor ends12/14and protrusion18(if used). For example, a first anchor end12may be fixedly secured to both the epicardium and the pericardium using an anchor device with open top and bottom surfaces as described in Vidlund et al., '519. The second anchor end14may be secured to epicardium, and the protrusion18may be secured to the pericardium (by using an anchor device for the protrusion18). The interconnecting member16may be fixedly connected to the protrusion18and adjustably connected to the second anchor end14(or visa-versa) such that the position of the protrusion18may be adjusted (e.g., cinched) relative to the second anchor end14. By virtue of the common pericardial connection between the first anchor12and the protrusion18, cinching the interconnecting member16between the protrusion18and the second anchor14also causes cinching between the protrusion18and the first anchor12, without requiring the interconnecting member16to be connected to the first anchor12.

The interconnecting member16may be elongate and will normally be in tension when implanted. The interconnecting member may comprise a flexible and biocompatible multifilament braid in the form of a string or strap, for example. If a string or chord is used, for example, an atraumatic pad (as seen inFIG. 5A) may be disposed on the interconnecting member16to avoid stress concentration on the heart wall by the interconnecting member16.

The interconnecting member16may be formed as described in U.S. Pat. No. 6,537,198 to Vidlund et al., the entire disclosure of which is incorporated herein by reference. In particular, the interconnecting member16may comprise a composite structure including an inner cable to provide mechanical integrity and an outer covering to provide biocompatibility. The inner cable of interconnecting member16may have a multifilament braided-cable of high performance polymeric fibers such as ultra high molecular weight polyethylene available under the trade names Spectra™ and Dyneema™, polyester available under the trade name Dacron™, or liquid crystal polymer available under the trade name Vectran™. The filaments forming the inner cable may be combined, for example, in yarn bundles of approximately 50 individual filaments, with each yarn bundle being approximately 180 denier, and two bundles may be paired together (referred to as 2-ply) and braided with approximately 16 total bundle pairs with approximately 20 to 50 picks per inch (number of linear yarn overlaps per inch).

The outer covering surrounding the inner cable of the interconnecting member16may provide properties that facilitate sustained implantation, and may thus be formed of a material that is biocompatible and allows for tissue ingrowth. For example, the outer covering surrounding the inner cable of the interconnecting member16may be made of a polyester material such as Dacron or ePTFE. If an atraumatic pad is used, it may be formed of, coated with, or covered by the same or similar material as the outer covering of the interconnecting member to promote tissue in-growth for additional anchoring effect. For example, the atraumatic pad may be formed of ePTFE which is biocompatible, promotes tissue in-growth, and conserves cross-sectiorial size and shape despite elongation.

The protrusion18may comprise a balloon, plug, or other mechanical spacer or structure, and may be fixedly or adjustably connected to the interconnecting member16. The protrusion18may be centered between the anchors12/14, or may be eccentrically positioned therebetween. One or more protrusions18may be used, and the protrusions may have various geometries depending on the desired allocation of forces acting on the heart wall. The protrusion18may be coated or covered by a tissue in-growth promoting material to secure the protrusion to the heart wall in the desired position, and the material may be highly elastic or otherwise stretchable to permit expansion of the protrusion18. Examples of suitable materials include ePTFE and polyester knits.

Description of Exemplary Implant Positions and Functions

With reference toFIGS. 2A-2C, cross sectional views of a patient's trunk at the level of the mitral valve MV of the heart H show the effects of implantable device10on mitral valve MV function. As seen inFIG. 2A, an incompetent mitral valve MV is shown during systole, as rendered incompetent by, for example, a dilated valve annulus AN, a displaced papillary muscle PM due to ventricular dilation or other mechanism. With reference toFIGS. 2B and 2C, the implantable device10may be positioned outside and adjacent the heart wall such that the device10acts on the mitral valve MV. As seen inFIGS. 2B and 2C, the formerly incompetent mitral valve MV is shown during systole as corrected with implantable device10. The implantable device10causes inward displacement of a specific portion of the heart wall adjacent the mitral valve MV resulting in re-configuration and re-shaping of the annulus AN and/or the papillary muscles PM, thus providing more complete closure of the mitral valve leaflets AL/PL during systole, as shown by closed coaptation line CL inFIGS. 2B and 2C.

The implantable device10may affect MV function by acting on the adjacent heart wall in several different modes. For example, in one mode of operation, the protrusion18(or the interconnecting member16if no protrusion is used) of the implantable device10may apply or focus an inward force against the heart wall acting on the MV. The back-up force (i.e., the substantially equal and opposite force to the inward force) may be provided by the interconnecting member16as fixed to the heart wall by the anchor ends12/14, the anatomical structure behind the protrusion18, or a combination thereof. In an alternative mode of operation, the implantable device10may act to cinch, compress or otherwise deform the heart wall surrounding the posterior aspect of the mitral valve MV by shortening the circumferential length thereof. In another alternative mode of operation, the implantable device10acts to both apply an inward force and cause circumferential shortening. In each of these modes of operation, the inward force and/or circumferential shortening may be applied throughout the cardiac cycle, or may only act during a portion of the cardiac cycle such as during systole.

The implantable device10may be implanted in a number of different positions, a select few of which are described herein for purposes of illustration, not necessarily limitation. Generally, the implantable device10may be positioned outside the epicardium of the heart wall adjacent the mitral valve MV, such as between the epicardium and pericardium, or between the pericardium and the pleural sac. Also generally, to maximize the effectiveness of the inward force, the implantable device10may be positioned to create a normal force against the heart wall that is generally orthogonal to the coaptation line CL formed by the leaflets PL/AL. This may be achieved, for example, by positioning the device10in a posterior-lateral projection of the mitral valve MV generally orthogonal to the middle tangent of the coaptation line CL as shown inFIGS. 2B and 2C.

A variety of long axis and short axis positions are contemplated and the particular combination may be selected to have the desired effect. In the short axis view as seen inFIGS. 2B and 2C, the implantable device10may extend along all of, a portion of, or beyond the posterior-lateral projection of the mitral valve MV. In the long axis view as seen inFIG. 3, the implantable device10may extend along all of, a portion of, or beyond the posterior-lateral projection of the mitral valve MV structures, including the papillary muscles PM, the chordae CT, the leaflets PL/AL, and the annulus AN. For example, the implantable device10may be positioned adjacent the annulus AN (e.g., extending slightly above and below the annulus AN near the AV groove), or adjacent the papillary muscles PM (e.g., extending slightly above and below the papillary muscles PM).

To avoid compression of the coronary arteries which typically reside near the surface of the heart wall, the implantable device10may have relatively small contact areas selected and positioned to establish contact with the heart wall while avoiding key anatomical structures. For example, as shown inFIG. 4, the implantable device10may be positioned with the first anchor12positioned between the proximal left anterior descending artery LAD and the proximal first obtuse marginal OM1, the protrusion positioned inferior of the circumflex artery CFX between the second obtuse marginal OM2and third obtuse marginal OM3, and the second anchor14positioned adjacent the posterior descending artery PDA. Alternatively, the implantable device10may have a relatively large surface area in contact with the heart wall to distribute the applied forces and avoid force focal points, particularly on the cardiac vasculature.

Description of Exemplary Delivery Techniques and Approaches

The implantable device10may be implanted using one or a combination of various methods and approaches. Generally, these delivery methods may be utilized to implant the device10in the pericardial space adjacent the posterior projection of the mitral valve MV. There are a number of different approaches and techniques for positioning the implantable device10as such, and these generally include surgical, transluminal and transthoracic techniques. For purposes of illustration, not necessarily limitation, an anterior transthoracic (subxiphoid) approach is described in more detail with reference toFIG. 11. Examples of other suitable approaches are described in more detail by Vidlund et al., '519.

Exemplary Embodiments of Implant Devices

With reference toFIGS. 5A-5D, perspective views of implantable devices110,210,610and710, respectively, are shown. Note that the side of the device110/210/610that faces the heart wall when implanted is the top side in the illustration. Devices110,210,610and710are further exemplary embodiments of the generic embodiment of implantable device10described previously, in which similar components have similar nomenclature, and such may be made, used and function in the same or similar manner.

As seen inFIG. 5A, implantable device110includes a first anchor112, a second anchor114, a interconnecting member116, and an optional protrusion118. Each of the first anchor112, second anchor114, interconnecting member116, and protrusion110may be loaded with a radiopaque material to render the visible under x-ray. In this embodiment, the interconnecting member116may comprise cables132and134, and the anchors112and114may comprise vacuum cups120with tissue piercing pins122, as will be described in more detail hereinafter. The anchor members112and114may be selectively attached, released and re-attached to the heart, and the protrusion118may be selectively adjusted relative to the anchor members112and114by adjusting the respective lengths of the interconnecting member116. The ends of the interconnecting member116may be fixedly attached to the anchors112and114, and adjustment of the length of the interconnecting member116is provided by a locking mechanism160as seen in and described with reference toFIG. 6A.

The anchors112and114may comprise a vacuum cup120with a tissue piercing pin122extending through the interior thereof. The cup120may be injection molded, for example, of a suitable biocompatible material such as PEEK, HDPE or PTFE, and the piercing pins122may be formed of stainless steel, for example. The piercing pins122are slidingly received in two bores disposed in the walls of the cup120. A locking mechanism such as mating geometry between the bores and the pins may be used to lock the pins in the pierced position as shown. A port124in communication with the interior of the cup120is provided for releasable connection to an anchor catheter400as shown and described with reference toFIGS. 6A and 6B.

Each cup120has a rim that conforms to the epicardial surface of the heart wall such that vacuum applied to the cup120by the anchor catheter400via port124draws the epicardial surface of the heart into the interior of the cup. With the epicardial tissue drawn inside the cup by the vacuum, the tissue piercing pin122may be advanced to pierce through the heart tissue and lock in the pierced position as shown. A lock mechanism such as illustrated inFIG. 5Emay be used to secure pins122. In this manner, the anchors112and114may be secured to the outside surface of the heart wall.

The protrusion118includes a base140, an inflatable balloon142mounted to the base140, and an outer covering144(shown partially cut-away) extending over the balloon142. The base140may be connected to a locking mechanism160(not visible) located on the opposite side of the balloon142, which in turn is connected to the interconnecting member116. The base140may comprise a flexible or semi rigid polymeric material, and the balloon142may comprise a compliant or non-complaint polymeric material conventionally used for implantable balloons. Outer covering144may comprise a material that promotes tissue in-growth to provide additional anchoring stability over time. The balloon142may be pre-filled, or may be filled during implantation, with a liquid that may solidify (cured) over time. To facilitate inflation of the balloon142, the interior of the balloon142may be in fluid communication with an inflation catheter via a lumen (not visible) extending through the locking mechanism160and the base140as described with reference toFIG. 6A.

The interconnecting member116may comprise two multifilament braided cables132and134. One end of each cable132and134may be fixedly connected to the anchors112and114, respectively, and the other ends of the cables132and134may be adjustably connected together by a locking mechanism160(not visible) attached to the base140of the protrusion118. The cables132and134may extend through a pair of atraumatic pads130that are secured to the base140of the protrusion118.

As seen inFIG. 5B, implantable device210includes a first anchor212, a second anchor214, a interconnecting member216, and a protrusion218. In this embodiment, the interconnecting member216includes a cable232extending through a strap230, with one end of the cable232fixedly connected to first anchor212, and the other end extending through second anchor214to which the cable may be selectively locked to adjust the length of the interconnecting member216. A locking mechanism260, similar to the locking mechanism160discussed with reference toFIG. 6A, may be connected to the second anchor214for selective tightening of and fixation to cable232. Otherwise, anchors212and214may be the same as anchors112and114described previously.

Strap230may vary in length as a function of the length of the cable232, and includes a plurality of pockets234that may be selectively filled with one or more plugs236to serve as the protrusion218, or the pockets234may remain empty. For example, selection of the pockets234to fill with plugs236may be made apply an inward force against the heart wall while avoiding or jumping over coronary arteries residing near the surface of the heart wall. Strap230may comprise a woven polymeric material as polyester, and the plug236may comprise a solid polymeric material such as PEEK, silicone, HDPE, PTFE or ePTFE.

As seen inFIG. 5C, implantable device610includes a first anchor612, a second anchor614, a interconnecting member616, and a protrusion618. In this embodiment, the interconnecting member616includes cable632extending through protrusion618, with one end of the cable632fixedly connected to first anchor612, and the other end extending through second anchor614to which the cable may be selectively locked to adjust the length of the interconnecting member616. A locking mechanism660, similar to the locking mechanism160discussed with reference toFIGS. 6A and 5E, may be connected to the second anchor614for selective tightening of and fixation to cable632. Anchors612and614include interior cavities620in fluid communication with a vacuum source to accommodate heart tissue for securement thereto by tissue piercing pins622. A port624in communication with the interior of the cup620is provided for releasable connection to an anchor catheter400or800as shown and described with reference to FIGS.6A/6B andFIG. 7, respectively. Recesses may be provided in each of the anchors612and614and the protrusion618for attachment of tissue in-growth promoting material such as Dacron fabric attached by suture-like material to cover the top, bottom and side surfaces. Otherwise, anchors612and614may be the same as anchors112and114described previously.

Protrusion618may include a center rotating member642coupled to cross member644by pivot connection646. The rotating member642may be rotated 90 degrees relative to cross member644about pivot646as indicated by arrows640. The rotating member642may be rotated as indicated by arrows640between a low profile delivery configuration wherein the rotating member642is generally aligned with the cross member644, and a deployed configuration wherein the rotating member642is generally orthogonal to the cross member644as shown. The rotating member642may be rotationally biased to the deployed configuration and may be locked in the deployed configuration. A pair of protrusions648may be disposed at opposite ends of the cross member644. The rotating member642in addition to the protrusions648may function as protrusions as described previously, while the gap therebetween may be used to avoid critical anatomical structures such as coronary vasculature.

As seen inFIG. 5D, implantable device710includes a first anchor712, a second anchor714, a interconnecting member716, and a protrusion718. In this embodiment, the interconnecting member716includes cable732fixedly attached to and extending through protrusion718, with both ends of the cable732adjustably connected to the anchors712and714by pins752to selectively lock and adjust the length of the interconnecting member716. Anchors712and714include interior cavities720in fluid communication with a vacuum source to accommodate heart tissue for securement thereto by tissue piercing pins722. A port724in communication with the interior of the cup720is provided for releasable connection to an anchor catheter400or800as shown and described with reference to FIGS.6A/6B orFIG. 7, respectively. Recesses may be provided in each of the anchors712and714and the protrusion718for attachment of tissue in-growth promoting material such as Dacron fabric attached by suture-like material to cover the top, bottom (inside anchor) and side surfaces (away from heart surface). Otherwise, anchors712and714may be the substantially the same as anchors112and114described previously.

Protrusion718may include a center rotating member742coupled to cross member744by pivot connection746. The rotating member742may be connected to the cross member744by an elastic ring and may be rotated 90 degrees relative to cross member744about pivot746as indicated by arrows740. The rotating member742may be rotated as indicated by arrows740between a low profile delivery configuration wherein the rotating member742is generally aligned with the cross member744, and a deployed configuration wherein the rotating member742is generally orthogonal to the cross member744as shown. The rotating member742may be rotationally biased to the deployed configuration and may be locked in the deployed configuration. A pair of protrusions748may be disposed at opposite ends of the cross member744. The rotating member742in addition to the protrusions748may function as protrusions as described previously, while the gap therebetween may be used to avoid critical anatomical structures such as coronary vasculature.

As seen inFIG. 5E, an example of a lock mechanism is shown to secure tissue piercing pins722and/or cable piercing pins752. The pins722/752may include a cylindrical shaft754and a sharpened tip756with a recess755therebetween. A braided multifilament material758such as Spectra™ is provided distal of the pins722/752in the anchor housing712/714to catch the recess755of the pins722/752when the tip756is advanced therethrough. This effectively locks the pins722/752in the advanced position to secure the interconnecting member716to the anchors712and714and/or to secure the anchors712and714to the heart tissue as will be described in more detail hereinafter.

Exemplary Embodiments of Delivery Devices

With reference toFIG. 6A, an example of a delivery system for delivery and implanting device110is shown. The delivery system generally includes a delivery catheter300and two anchor catheters400, all of which are releasably connected to the implantable device110. The illustrated delivery system is particularly suitable for delivering implantable device110, but may also be modified for delivery of implantable devices210,610and710. The delivery system may be configured in terms of size, length, flexibility, radiopacity, etc., to facilitate a transthoracic delivery approach such as the subxiphoid delivery approach described with reference toFIG. 11.

The delivery catheter300includes a tubular shaft310defining an inflation lumen and two cable lumens extending therethrough. A pair of push tubes312extend along side the tubular shaft310and slidably accommodate push rods332and334. The distal ends of the tubular shaft310and push tubes312are coupled to the locking mechanism160by a release mechanism326such as a threaded, pinned or other releasable connection, such as the pin mechanism illustrated inFIG. 5E. The push rods332and334may be advanced or retracted to selectively actuate individual pins162and164respectively in the lock mechanism160such that the pins162and164pass through the cables132and134, respectively, and thus lock the cables relative thereto. Reference may be made to published U.S. Patent Application No. 2003/0050529 to Vidlund et al., the disclosure of which is incorporated herein by reference, for an example of a similar locking mechanism.

The proximal end of the tubular shaft310is connected to a manifold including connectors322and324and inflation port318. The inflation lumen of the tubular shaft310provides fluid communication between the interior of the balloon142and the inflation port318of the manifold314for connection to an inflation device (not shown) to facilitate inflation and deflation of the balloon142. If no balloon142is used, the inflation lumen and associated parts may be eliminated. The cable lumens of the tubular shaft310accommodate the proximal portions of the cables132and134for connection to a sizing device500via connectors322and324as described with reference toFIG. 8, and for positioning the implant110relative to the anchors112and114.

With additional reference toFIG. 6B, the anchor catheters400are essentially mirror constructions of each other, and include a tubular shaft410. A slit guide tube412extends along side a portion of the tubular shaft410to guide the cable132/134before the delivery catheter300is advanced as will be discussed in more detail hereinafter. A proximal end of the tubular shaft410is connected to a manifold418including a vacuum port416and a gasketed port415containing a push rod414. A distal end of the tubular shaft410is releasably connected to the anchor112/114by a release mechanism420that may comprise a threaded, pinned or other releasable connection, for example. The tubular shaft410includes a vacuum lumen (not visible) extending therethrough to provide a fluid path from the interior of the cup120to the vacuum port416to facilitate connection to a vacuum source. The push rod414is disposed in the vacuum lumen of the catheter shaft410and may be slid therethrough to selectively advance or retract the piercing pin122in the cup120.

With reference toFIG. 7, an example of a delivery system for delivery and implanting device710is shown. The delivery system generally includes a two anchor catheters800, both of which are releasably connected to the implantable device710. The illustrated delivery system is particularly suitable for delivering implantable devices210,610and710, but may also be modified for delivery of implantable device110. The delivery system may be configured in terms of size, length, flexibility, radiopacity, etc., to facilitate a transthoracic delivery approach such as the subxiphoid delivery approach described with reference toFIG. 11.

The anchor catheters800are essentially mirror constructions of each other (with the exception of split tube813), and include a tubular shaft810comprising a directional catheter construction connected to a handle850. The directional catheter shaft810and associated handle850are available from Medamicus, Inc. of Plymouth, Minn. Handle850generally includes a grip portion852and a thumb knob854which actuates control wires in the directional catheter shaft810to permit selective bi-directional lateral deflection of the distal end thereof. The directional catheter shaft810and associated handle850accommodate a push rod (not visible) extending therethrough for actuation of the tissue piercing pin722. The push rod for the tissue piercing pin722may comprise a stainless steel mandrel, for example, with a distal end abutting the proximal end of the tissue piercing pin722, and a proximal end connected to a knob814. The directional catheter shaft810and associated handle850also accommodate a vacuum lumen (not visible) extending therethrough to define a fluid path to the interior720of the anchor712/714, such that a vacuum source (not shown) may be connected to vacuum port816on the handle850to provide suction at the anchor712/714to facilitate stabilization and securement to the outside of the heart wall.

Each of the anchor catheters800also includes a side tube812coextending with the directional catheter shaft810. Side tube812accommodates the interconnecting member732, a push rod (not visible) for actuation of the interconnecting member piercing pin752, and a pull wire (not visible) for release of the anchor712/714as described in more detail below. The interconnecting member732extends through the side tube812from a proximal port822/824through the anchor712/714to the protrusion718. To accommodate the interconnecting member732during initial delivery of the implant710, a slotted side tube813may be provided on one of the catheters800.

The push rod for the interconnecting member piercing pin752may comprise a stainless steel mandrel, for example, with a distal end abutting the proximal end of the interconnecting member piercing pin752, and a proximal end connected to knob832/834. A pair of guide loops815may be provided distal of the side tube to guide the interconnecting member732, and a guide tube862/864may be provided distal of the side tube812to guide the push rod for the interconnecting member piercing pin752.

The distal end of the directional catheter shaft810is connected to anchor712/714by a releasable connection820, which may comprise a threaded type connection or a cotter pin type connection, for example. In the illustrated embodiment, the releasable connection820comprises a cotter pin type connection, with the pull wire (not visible) proximally connected to pull knob842/844, and distally extending through aligned holes (not visible) in the anchor712/714and in the fitting on the distal end of the directional catheter shaft810. By pulling proximally on pull knob842/844, the anchor712/714may be released from the distal end of the directional catheter shaft810.

With reference toFIG. 8, a sizing device500is shown for adjusting the tension of interconnecting member116,216,616, or716and in particular cable members132/134,232,632or732. Sizing device500includes an elongate interconnecting member receiving tube510having a distal end including an engagement member512and a proximal end516connected to a preferably clear measuring tube514having a measuring scale515marked thereon. An inner tube518is disposed in the measuring tube514and is connected to a proximal end of the cable member to be tensioned. A lock mechanism522and release button524(biased in locked position) are connected to the proximal end of the measuring tube514to selectively lock the inner tube518relative to the measuring tube. A pin522protruding from inner tube518extends through a slot in measuring tube514to prevent relative rotation. An indicator (not visible) on the inner tube518adjacent the pin522is visible through transparent measuring tube514to facilitate linear measurement relative to scale515.

To connect the cable to the inner rod or tube518, the cable132/134,232,632or732is threaded through receiving tube510, through measuring tube514, through the inner tube518, and placed in a retaining mechanism520disposed on the inner tube518. Engagement member512may be connected to one of the connectors322/324or822/824on the delivery catheter, or directly to the lock mechanism160of device110or lock mechanism of device210. With this arrangement, the inner tube518may be pulled proximally relative to the measuring tube514to apply tension to the cable and thus selectively adjust the tightness or degree of cinching of the implantable device110/210/610/710, and/or selectively adjust the position of the protrusion relative to the anchor ends.

Exemplary Embodiments of Access Devices

With reference toFIG. 9, an exemplary embodiment of an access device1000is shown. Access device1000provides for less invasive surgical access from a point outside the patient's body, through a transthoracic port to the pericardial space around the patient's heart, as will be described in more detail with reference toFIG. 11. A variety of pericardial access devices may be used to delivery the implantable device10, and thus access device1000is shown by way of example not limitation. In this exemplary embodiment, access device1000includes an outer tube1100, a securement tube1200, and a cutter tube1300. The securement tube1200is slidably and coaxially disposed in outer tube1100, and similarly, the cutter tube1300is slidably and coaxially disposed in the securement tube1200.

Outer tube1100may comprise a rigid tubular shaft1102formed of stainless steel, for example, having a lumen extending therethrough. A cap1104having an interior recess (not visible) may be connected to the distal end of the shaft1102. A handle1106may be connected to a proximal end of the tubular shaft1102to facilitate manual manipulation. A vacuum port1108may be incorporated into the handle1106to facilitate connection to a vacuum source (not shown) for establishing a vacuum in the lumen extending through the tubular shaft1102.

The securement tube1200may comprise a rigid tubular shaft1202formed of stainless steel, for example, having a lumen extending therethrough. An annular array of pericardium piercing pins1204may be disposed at the distal end of the tubular shaft1202, and are sized to fit in the recess inside cap1104at the distal end of the outer tube1100as will be discussed in more detail with reference toFIG. 10. A handle1206may be disposed at the proximal end of the tubular shaft1202to facilitate manual manipulation and to act as a stop to prevent the securement tube1200from advancing fully into outer tube1100. A vacuum hole1208may be provided through the side of the tubular shaft1202to provide a fluid path from the interior of the outer tube1100to the interior of the securement tube1200, thus permitting a vacuum to be established inside the tubular shaft1202of the securement tube1200by application of a vacuum to vacuum port1108.

The cutter tube1300may comprise a rigid tubular shaft1302formed of stainless steel, for example, having a lumen extending therethrough. An annular cutting edge1304may be disposed at the distal end of the tubular shaft1302. An annular ring1306may be disposed adjacent the distal end of the tubular shaft1302to provide a slidable fluid seal with the inside surface of the tubular shaft1202of the securement tube1200. A series of vacuum holes1308may be provided through the side of the tubular shaft1302distal of the annular ring1306to provide a fluid path from the interior of the securement tube1200to the interior of the cutter tube1300, thus permitting a vacuum to be established inside the tubular shaft1302of the cutter tube1300by application of a vacuum to vacuum port1108. A handle1310may be disposed at the proximal end of the tubular shaft1302to facilitate manual manipulation and to act as a stop to prevent the cutter tube1300from advancing fully into securement tube1200. A visualization device1320such as a camera or eye piece1322and light source1324may be connected to the proximal end of the tubular shaft1302to permit direct visualization down the lumen of the cutter tube1300. Alternatively, an intracardiac echo device may be inserted therethrough, using vacuum for stability, to permit visualization and guidance on the epicardial surface.

With reference toFIGS. 9 and 10, the operation of the distal portion of the access device1000may be appreciated. The cutter tube1300and the securement tube1200may be disposed in the outer tube1100with the distal ends thereof slightly retracted. The outer tube1100may be inserted through a transthoracic port until the distal cap1104engages the pericardium (PC) surrounding the heart. Vacuum is applied to port1108thus drawing the PC into the lumen of the outer tube1100, the securement tube1200, and the cutter tube1300to form inward protrusion. The vacuum also draws the PC into the interior recess of the cap1104to form an annular fold. The securement tube1200may then be advanced distally until the array of pins1204passes through the annular fold in the PC, thus mechanically securing and sealing the PC to the access device1000. The cutter tube1300may then be advanced distally until the annular cutting edge1304cuts the inward protrusion of the PC, leaving the annular fold of the PC secured to the access device1000. With the annular fold of the PC mechanically and sealingly connected to the distal end of the access device1000, and with the outside diameter of the access device1000sized to form a seal in the transthoracic port, a sealed access path is established to the pericardial space that is isolated from the pleural space.

Exemplary Embodiments of Access and Delivery Methods

InFIG. 11, a transthoracic anterior approach is shown as a dashed line with a distal arrow. This anterior approach may comprise a subxiphoid approach to establish access to the pericardial space, similar to the technique described by Kaplan et al. in U.S. Pat. No. 6,423,051 the entire disclosure of which is incorporated herein by reference. An alternative lateral or posterior approach may utilize similar tools and techniques to access the pericardial space from the side or back between the ribs (intercostal space), similar to the techniques described by Johnson in U.S. Pat. No. 5,306,234 the entire disclosure of which is incorporated herein by reference.

Generally speaking, once pericardial access is established with an access system as described with reference toFIGS. 9 and 10, a delivery system as described with reference toFIGS. 6 and 7may be used to advance and manipulate the device10to the desired deployment position in the pericardial space adjacent the mitral valve MV or a specific part thereof. Assessment of the position and function of the device10relative to internal mitral valve MV structures such as leaflets AL/PL, papillary muscles PM, and regurgitant jet may be performed with ultrasonic imaging such as trans-esophageal, intracardiac or epicardial echocardiography, or x-ray fluoroscopy. These techniques may also be used monitor the adjustment of the size and/or tension of the device10with an adjustment device as described with reference toFIG. 8until the desired acute effect is established. Once in the desired position, the device10may be detached or otherwise disengaged from the distal end of the delivery system, which is subsequently removed.

The following detailed example of a delivery method using the delivery system and implant illustrated inFIG. 7is described by way of example, not limitation, and may be applied to other delivery systems and implants described herein. This method may be broken down into six general steps: (1) establish pericardial access; (2) deliver the first anchor (e.g., near the PDA); (3) deliver the protrusion; (4) deliver the second anchor (e.g., near the LAD); (5) adjust the implant to achieve the desired effect on MV function; and (6) remove the delivery system leaving the implant in place on the outside of the heart.

To establish pericardial access, a needle may be inserted into the chest cavity below the xiphoid as generally shown inFIG. 11. A guide wire (e.g., 0.035″ diameter) may then be inserted into the needle and advanced toward the cardiac space. The needle may then be removed leaving the guide wire in place, and one or more dilators may then be advanced over the guide wire to dilate the percutaneous path. The dilator(s) may then be removed, and the access device illustrated inFIG. 9may be advanced over the wire adjacent the pericardium. Fluoroscopic visualization (e.g., AP and lateral views) may be used to confirm the desired pericardial access site.

Using the access device illustrated inFIG. 9, vacuum may be applied to cause the pericardium to be sucked into the distal end thereof, and the tissue piercing pins may be actuated to mechanically secure the pericardium to the access device. The cutter tube may then be advanced to cut and remove a portion of the pericardium in the distal end of the access device, thus establishing a path from the exterior of the body to the pericardial space around the heart.

Initially, the interconnecting member may be loaded into the first anchor and anchor catheter with one side of the interconnecting member extending through the side tube and the other side of the interconnecting member extending through the slotted side tube. Before delivering the anchor, angiographic visualization of the left and/or right coronary arteries may be performed to map the locations of the critical arteries. To deliver the first anchor near the PDA as shown inFIG. 4, for example, the anchor catheter may be manipulated through the access device until the anchor is adjacent the PDA near the last obtuse marginal (OM3), using fluoroscopic visualization to aid navigation. After ascertaining that the first anchor is not positioned over any coronary arteries, vacuum may be applied to the first anchor to temporarily stabilize the anchor on the outside of the heart wall and to pull tissue into the interior of the anchor. The tissue piercing pins may then be actuated to secure the first anchor to the heart wall.

The protrusion may then be advanced along the first anchor catheter by removing one end of the interconnecting member from the slotted tube on the anchor catheter, inserting it through the protrusion and fixing the protrusion midway on the interconnecting member. A delivery tube may be placed about the protrusion to retain it in the delivery configuration, and the delivery tube with the protrusion therein may then be inserted through the access device. By pulling on the opposite end of the interconnecting member and by manipulating the delivery tube, the protrusion may be advanced until it is adjacent the first anchor.

Before delivering the second anchor near the LAD as shown inFIG. 4, the interconnecting member may be inserted into the second anchor and through the side tube of the second anchor catheter. The second anchor may then be slid over the interconnecting member using the anchor catheter, passing through the access device and into the pericardial space. With the aid of fluoroscopic guidance, the second anchor may be positioned next to the junction of the LAD and CFX as seen inFIG. 4, for example. After ascertaining that the second anchor is not positioned over any coronary arteries, vacuum may be applied to the second anchor to temporarily stabilize the anchor on the outside of the heart wall and to pull tissue into the interior of the anchor. The tissue piercing pins may then be actuated to secure the second anchor to the heart wall.

With the first and second anchors secured to the outside of the heart wall, and the protrusion extending therebetween, the interconnecting member may be tightened or cinched using the device illustrated inFIG. 8, for example. MV function may be simultaneously observed using TEE or ICE, and the degree of cinching of the interconnecting member and/or the position of the protrusion may be adjusted to obtain the desired reduction in MV regurgitation (MVR).

With the aid of fluoroscopy, correct anchor positioning may be verified and adequate blood flow may be confirmed in the left coronary arteries. After confirming correct positioning and adequate reduction in MVR, the interconnecting members may be secured by actuating interconnecting member piercing pins with the associated push rods, and the directional catheter shaft may be disconnected from the anchors by actuating the releasable connection with the associated pull wires.

The delivery system may then be removed, and the interconnecting members may be trimmed adjacent the anchors with a cutting device such as an elongate cautery tool. The access device may be removed and the sub-xiphoid access site may be closed using sutures.

From the foregoing, it will be apparent to those skilled in the art that the present invention provides, in exemplary non-limiting embodiments, devices and methods for improving the function of a valve (e.g., mitral valve) by positioning an implantable device outside and adjacent the heart wall such that the device applies an inward force against the heart wall or otherwise deforms the heart wall thus acting on the valve to improve leaflet coaptation. Further, those skilled in the art will recognize that the present invention may be manifested in a variety of forms other than the specific embodiments described and contemplated herein. Accordingly, departures in form and detail may be made without departing from the scope and spirit of the present invention as described in the appended claims.