Devices and Systems for Reshaping a Heart Valve Annulus, Using a Tensioning Implant
Implants or systems of implants apply a selected force vector or a selected combination of force vectors within or across the left atrium, which allow mitral valve leaflets to better coapt. The implants or systems of implants make possible rapid deployment, facile endovascular delivery, and full intra-atrial retrievability. The implants or systems of implants also make use of strong fluoroscopic landmarks.
Latest MVRx, INC. Patents:
- Delivery system and methods for reshaping a heart valve annulus, including the use of magnetic tools
- Devices, systems and methods for reshaping a heart valve annulus
- Delivery system and methods for reshaping a heart valve annulus, including the use of magnetic tools
- Devices, systems, and methods for reshaping a heart valve annulus
- Devices, systems, and methods for reshaping a heart valve annulus
This application is a divisional of co-pending U.S. patent application Ser. No. 10/894,433, filed Jul. 19, 2004, now U.S. Pat. No. 8,956,407, issued Feb. 17, 2015, entitled “Methods for Reshaping a Heart Valve Annulus, Using a Tensioning Implant,” which is a continuation-in-part of U.S. patent application Ser. No. 10/846,850, filed May 14, 2004, now U.S. Pat. No. 8,784,482, issued Jul. 22, 2014, entitled “Devices, Systems, and Methods for Reshaping a Heart Valve Annulus, which is a continuation-in-part of U.S. patent application Ser. No. 10/677,104, filed Oct. 1, 2003, and entitled “Devices, Systems, and Methods for Reshaping a Heart Valve Annulus,” which claims the benefit of U.S. Provisional Patent Application Ser. No. 60/429,444, filed Nov. 26, 2002, and entitled “Heart Valve Remodeling Devices,” and which is a continuation-in-part of U.S. patent application Ser. No. 09/666,617, filed Sep. 20, 2000, now U.S. Pat. No. 6,893,459, issued May 17, 2005, and entitled “Heart Valve Annulus Device and Methods of Using Same,” which is incorporated herein by reference. This application is also a continuation-in-part of U.S. patent application Ser. No. 10/695,433, filed Oct. 28, 2003, now U.S. Pat. No. 7,291,168, issued Nov. 6, 2007, entitled “Methods and Devices for Heart Valve Treatments,” which is a continuation of Patent Cooperation Treaty Application Serial No. PCT/US02/31376, filed Oct. 1, 2002, and entitled “Systems and Devices for Heart Valve Treatments,” which claimed the benefit of U.S. Provisional Patent Application Ser. No. 60/326,590, filed Oct. 1, 2001, which are incorporated herein by reference. This application is also a continuation-in-part of U.S. patent application Ser. No. 10/676,729, filed Oct. 1, 2003, now U.S. Pat. No. 7,527,646, issued May 5, 2009, and entitled “Devices, Systems, and Methods for Retaining a Native Heart Valve Leaflet,” which claims the benefit of U.S. Provisional Patent Application Ser. No. 60/429,462, filed Nov. 26, 2002, and entitled “Heart Valve Leaflet Retaining Devices,” which are incorporated herein by reference. This application is also a continuation-in-part of U.S. patent application Ser. No. 10/676,815, filed Oct. 1, 2003, now U.S. Pat. No. 7,381,220, issued Jun. 3, 2008, and entitled “Devices, Systems and Methods for Supplementing, Repairing or Replacing a Native Heart Valve Leaflet,” which claims the benefit of U.S. Provisional Patent Application Ser. No. 60/429,709, filed Nov. 26, 2002, and entitled “Neo-Leaflet Medical Device,” which are incorporated herein by reference.
FIELD OF THE INVENTIONThe invention is directed to devices, systems, and methods for improving the function of a heart valve, e.g., in the treatment of mitral valve regurgitation.
BACKGROUND OF THE INVENTION I. The Anatomy of a Healthy HeartThe heart (see
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. The ventricles are the blood-discharging chambers. A wall composed of fibrous and muscular parts, called the interatrial septum separates the right and left atria (see
An anatomic landmark on the interatrial septum is an oval, thumbprint sized depression called the oval fossa, or fossa ovalis (shown in
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 (see
At the beginning of ventricular diastole (i.e., ventricular filling) (see
The opening and closing of heart valves occur primarily as a result of pressure differences. For example, the opening and closing of the mitral valve occurs as a result of the pressure differences between the left atrium and the left ventricle. During ventricular diastole, when ventricles are relaxed, the venous return of blood from the pulmonary veins into the left atrium causes the pressure in the atrium to exceed that in the ventricle. As a result, the mitral valve opens, allowing blood to enter the ventricle. As the ventricle contracts during ventricular systole, the intraventricular pressure rises above the pressure in the atrium and pushes the mitral valve shut.
The mitral and tricuspid valves are defined by fibrous rings of collagen, each called an annulus, which forms a part of the fibrous skeleton of the heart. The annulus provides attachments for the two cusps or leaflets of the mitral valve (called the anterior and posterior cusps) and the three cusps or leaflets of the tricuspid valve. The leaflets receive chordae tendineae from more than one papillary muscle. In a healthy heart, these muscles and their tendinous cords support the mitral and tricuspid valves, allowing the leaflets to resist the high pressure developed during contractions (pumping) of the left and right ventricles.
As
Also in the vicinity of the posterior mitral valve annulus are the coronary sinus and its tributaries. These vessels drain the areas of the heart supplied by the left coronary artery. The coronary sinus and its tributaries receive approximately 85% of coronary venous blood. The coronary sinus empties into the posterior of the right atrium, anterior and inferior to the fossa ovalis (see
When the left ventricle contracts after filling with blood from the left atrium, the walls of the ventricle move inward and release some of the tension from the papillary muscle and chords. The blood pushed up against the under-surface of the mitral leaflets causes them to rise toward the annulus plane of the mitral valve. As they progress toward the annulus, the leading edges of the anterior and posterior leaflet come together forming a seal and closing the valve. In the healthy heart, leaflet coaptation occurs near the plane of the mitral annulus. The blood continues to be pressurized in the left ventricle until it is ejected into the aorta. Contraction of the papillary muscles is simultaneous with the contraction of the ventricle and serves to keep healthy valve leaflets tightly shut at peak contraction pressures exerted by the ventricle.
In a healthy heart (see
Valve malfunction can result from the chordae tendineae (the chords) becoming stretched, and in some cases tearing. When a chord tears, the result is a leaflet that flails. Also, a normally structured valve may not function properly because of an enlargement of or shape change in the valve annulus. This condition is referred to as a dilation of the annulus and generally results from heart muscle failure. In addition, the valve may be defective at birth or because of an acquired disease.
Regardless of the cause (see
Mitral regurgitation is a condition where, during contraction of the left ventricle, the mitral valve allows blood to flow backwards from the left ventricle into the left atrium. This has two important consequences.
First, blood flowing back into the atrium may cause high atrial pressure and reduce the flow of blood into the left atrium from the lungs. As blood backs up into the pulmonary system, fluid leaks into the lungs and causes pulmonary edema.
Second, the blood volume going to the atrium reduces volume of blood going forward into the aorta causing low cardiac output. Volume overloads the ventricle, as the excess blood in the atrium over-fills the ventricle during each cardiac cycle.
Mitral regurgitation is measured on a numeric Grade scale of 1+ to 4+ by either contrast ventriculography or by echocardiographic Doppler assessment. Grade 1+ is trivial regurgitation and has little clinical significance. Grade 2+ shows a jet of reversed flow going halfway back into the left atrium. Grade 3 regurgitation shows filling of the left atrium with reversed flow up to the pulmonary veins and a contrast injection that clears in three heart beats or less. Grade 4 regurgitation has flow reversal into the pulmonary veins and a contrast injection that does not clear from the atrium in three or fewer heart beats.
Mitral regurgitation is categorized into two main types, (i) organic or structural and (ii) functional. Organic mitral regurgitation results from a structurally abnormal valve component that causes a valve leaflet to flail upward and leak during systole. Functional mitral regurgitation results from annulus dilation due to primary congestive heart failure, the latter of which is itself generally surgically untreatable, and not due to a reversible cause like severe ischemia or primary valvular heart disease.
Organic mitral regurgitation is seen when a disruption of the seal occurs at the free leading edge of the leaflet due to a ruptured chord or papillary muscle making the leaflet flail; or if the leaflet tissue is redundant, the valves may prolapse the level at which coaptation occurs higher into the atrium with further prolapse opening the valve higher in the atrium during ventricular systole.
Functional mitral regurgitation occurs as a result of dilation of heart and mitral annulus secondary to heart failure, most often as a result of coronary artery disease or idiopathic dilated cardiomyopathy. Comparing a healthy annulus in
The fibrous mitral annulus is attached to the anterior mitral leaflet in one-third of its circumference. The muscular mitral annulus constitutes the remainder of the mitral annulus and is attached to by the posterior mitral leaflet. The anterior fibrous mitral annulus is intimate with the central fibrous body, the two ends of which are called the fibrous trigones. Just posterior to each fibrous trigone is the commissure of which there are two, the anterior and the posterior commissure. The commissure is where the anterior leaflet meets the posterior leaflet at the annulus.
As before described, the central fibrous body is also intimate with the non-coronary leaflet of the aortic valve. The central fibrous body is fairly resistant to elongation during the process of mitral annulus dilation. It has been shown that the great majority of mitral annulus dilation occurs in the posterior two-thirds of the annulus known as the muscular annulus. One could deduce thereby that, as the annulus dilates, the percentage that is attached to the anterior mitral leaflet diminishes.
In functional mitral regurgitation, the dilated annulus causes the leaflets to separate anterior from posterior leaflet at their coaptation points in all phases of the cardiac cycle. Onset of mitral regurgitation may be acute, or gradual and chronic in either organic or in functional mitral regurgitation.
In dilated cardiomyopathy of ischemic or of idiopathic origin, the mitral annulus can dilate to the point of causing functional mitral regurgitation. It does so in approximately twenty-five percent of patients with congestive heart failure. If subjected to exercise, echocardiography shows the incidence of functional mitral regurgitation in these patients rises to over fifty percent.
Functional mitral regurgitation is a significantly aggravating problem for the dilated heart, as is reflected in the increased mortality of these patients compared to otherwise comparable patients without functional mitral regurgitation. One mechanism by which functional mitral regurgitation aggravates the situation in these patients is through increased volume overload imposed upon the ventricle. Due directly to the leak, there is increased work the heart is required to perform in each cardiac cycle to eject blood antegrade through the aortic valve and retrograde through the mitral valve. The latter is referred to as the regurgitant fraction of left ventricular ejection. This is added to the forward ejection fraction to yield the total ejection fraction. A normal heart has a forward ejection fraction of seventy percent. With functional mitral regurgitation and dilated cardiomyopathy the ejection fraction is typically less than thirty percent. If the regurgitant fraction is half the ejection fraction in the latter group the forward ejection fraction can be as low as fifteen percent.
III. Prior Treatment ModalitiesIn the treatment of mitral valve regurgitation, diuretics and/or vasodilators can be used to help reduce the amount of blood flowing back into the left atrium. An intra-aortic balloon counterpulsation device is used if the condition is not stabilized with medications. For chronic or acute mitral valve regurgitation, surgery to repair or replace the mitral valve is often necessary.
Currently, patient selection criteria for mitral valve surgery are very selective. Patients will ideally have normal ventricular function, general good health, and a predicted lifespan of greater than 3 to 5 years, NYHA Class III or IV symptoms, and at least Grade 3 regurgitation as indications for mitral surgery. Younger patients with less severe symptoms may be indicated for early surgery if mitral repair is anticipated. The most common surgical mitral repair procedure is for organic mitral regurgitation due to a ruptured chord on the middle scallop of the posterior leaflet.
In conventional annuloplasty ring repair, the posterior annulus is reduced along its length with sutures passed through a surgical annuloplasty sewing ring cuff. The goal of such a repair is to bring the posterior mitral leaflet forward toward to the anterior leaflet to better allow coaptation.
Surgical edge-to-edge juncture repairs, which can be performed endovascularly, are also made, in which a mid valve leaflet to mid valve leaflet suture or clip is applied to keep these points of the leaflet held together throughout the cardiac cycle. Edwards Life Sciences Corporation and Evalve Inc. have developed, respectively, a transvascular suture and a clip to grasp and bond the two mitral leaflets in the beating heart.
Grade 3+ or 4+ organic mitral regurgitation may be repaired with such edge-to-edge technologies. This is because, in organic mitral regurgitation, the problem is not the annulus but in the central valve components.
However, functional mitral regurgitation can persist at a high level, even after edge-to-edge repair, particularly in cases of high Grade 3+ and 4+ functional mitral regurgitation.
In another emerging technology, the coronary sinus is mechanically deformed through endovascular means applied and contained to function solely within the coronary sinus. Early clinical reports in humans report the inability of these endovascular coronary sinus technologies to reshape the mitral annulus.
It is reported that twenty-five percent of the six million Americans who will have congestive heart failure will have functional mitral regurgitation to some degree. This constitutes the 1.5 million people with functional mitral regurgitation. Of these, the idiopathic dilated cardiomyopathy accounts for 600,000 people. Of the remaining 900,000 people with ischemic disease, approximately half have functional mitral regurgitation due solely to dilated annulus.
By interrupting the cycle of progressive functional mitral regurgitation, it has been shown in surgical patients that survival is increased and in fact forward ejection fraction increases in many patients. The problem with surgical therapy is the significant insult it imposes on these chronically ill patients with high morbidity and mortality rates associated with surgical repair.
The need remains for simple, cost-effective, and less invasive devices, systems, and methods for treating dysfunction of a heart valve, e.g., in the treatment of organic and functional mitral valve regurgitation.
SUMMARY OF THE INVENTIONThe invention comprises various aspects, which are separate and distinct but which can be combined for use, if desired.
One aspect of the invention provides devices, systems, and methods for treating a mitral heart valve using an anchor structure that is located within the great cardiac vein.
In one embodiment, the devices, systems, and methods install the anchor structure within the great cardiac vein adjacent a length comprising at least a portion of a posterior annulus of the mitral valve. The devices, systems, and methods couple a posterior region of an implant to the anchor structure within great cardiac vein and extend the implant across the left atrium, through an interatrial septum, and into a right atrium. The devices, systems, and methods tension the implant and anchor an anterior region of the implant to tissue in or near the right atrium to maintain the tension. The tension applied by the implant can improve septal-to-lateral dimensions of the valve and thereby lead to improved leaflet coaption to ameliorate functional mitral valve regurgitation. In the case of organic mitral valve regurgitation, the tension applied by the implant can serve the stabilize the posterior annulus in the manner of an annuloplasty ring, to resist change in annulus size during the cardiac cycle.
In one embodiment, the anchor structure can also serve to consolidate the great cardiac vein into a unified physical structure along its length. In this arrangement, the tension applied to the implant is uniformly distributed as a force vector to atrial tissue adjacent the posterior mitral valve annulus through the consolidated great cardiac vein. The consolidation of tissue can enhance the beneficial effects of the implant.
In one embodiment, the devices, systems, and methods conjoin the great cardiac vein to the left ventricle in a tissue region between the consolidated great cardiac vein and the left ventricle. In this arrangement, the implant is configured, when placed into tension, to apply a force vector upon the tissue consolidating anchor structure within the great cardiac vein. The force vector xcan be upward, inward, or a combination of both. The force vector is directed by the conjoined tissue region to the left ventricle, to relieve tension on the annulus. As before, the beneficial effects achieved can be thereby further enhanced.
Another aspect of the invention provides devices, systems, and methods for treating a mitral heart valve using an elongated structure sized and configured to be deployed in tension a circumferential path within the great cardiac vein adjacent a posterior annulus of the mitral valve. The structure includes an end anchoring region sized and configured to extent from the coronary sinus into the right atrium. An anchor couples to the end anchoring region on the interatrial septum in the right atrium. The tension applied by the implant can improve septal-to-lateral dimensions of the valve and thereby lead to improved leaflet coaption to ameliorate functional mitral valve regurgitation. In the case of organic mitral valve regurgitation, the tension applied by the implant can serve the stabilize the posterior annulus in the manner of an annuloplasty ring, to resist change in annulus size during the cardiac cycle.
Another aspect of the invention provides devices, systems, and methods for treating a mitral heart valve using an elongated structure sized and configured to be deployed as a loop at least in part within the great cardiac vein. In this arrangement, the elongated structure includes first and second end anchoring regions. The elongated structure also includes an intermediate region coupled to the first and second end anchoring regions. Each end anchoring region is sized and configured, in use, to extend into the right atrium, while the intermediate region is sized and configured to extend outside the right atrium in a circumferential path within the great cardiac vein adjacent a posterior annulus of the mitral valve. An anchor couples to the first and second end anchoring regions in the right atrium or a vena cava to hold the intermediate region in tension within the great cardiac vein. The tension applied by the implant can improve septal-to-lateral dimensions of the valve and thereby lead to improved leaflet coaption to ameliorate functional mitral valve regurgitation. In the case of organic mitral valve regurgitation, the tension applied by the implant can serve the stabilize the posterior annulus in the manner of an annuloplasty ring, to resist change in annulus size during the cardiac cycle.
Another aspect of the invention provides devices, systems, and methods for placing implants within a heart chamber. A first implant is deployed within a heart vessel adjacent to a heart chamber, and a second implant is deployed within the heart chamber. According to this aspect of the invention, a region of the second implant within the heart chamber is magnetically attracting to a region of the first implant within the heart vessel e.g., so that the region of the second implant can be coupled to the region of the first implant within the heart vessel.
Other features and advantages of the invention shall be apparent based upon the accompanying description, drawings, and claims.
Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention, which may be embodied in other specific structure. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.
I. Trans-Septal Implants for Direct Shortening of the Minor Axis of a Heart Valve AnnulusA. Implant Structure
The posterior anchoring region 14 is sized and configured to be anchored in a region of atrial tissue above the posterior mitral valve annulus. This region is preferred, because it generally presents more tissue mass for obtaining purchase of the posterior anchoring region 14 than in a tissue region at or adjacent to the posterior annulus. Engagement of tissue at this supra-annular location also avoids encroachment of and risk of injury to the circumflex coronary artery.
The anterior anchoring region 16 is sized and configured to be anchored, upon passing into the right atrium through the septum, to tissue in or near the right atrium. For example, as is shown in
As will be described in greater detail later, in an alternative embodiment (see, e.g.,
In use, the spanning region or bridging element 12 can be placed into tension between the two tissue anchoring regions 14 and 16. The implant 10 thereby serves to apply a direct mechanical force generally in posterior to anterior direction across the left atrium. The direct mechanical force can serve to shorten the minor axis of the annulus. In doing so, the implant 10 can also reactively reshape the annulus along its major axis and/or reactively reshape other surrounding anatomic structures. It should be appreciated, however, the presence of the implant 10 can serve to stabilize tissue adjacent the heart valve annulus, without affecting the length of the minor or major axes.
It should be appreciated that, when situated in other valve structures, the axes affected may not be the “major” and “minor” axes, due to the surrounding anatomy. It should also be appreciated that, in order to be therapeutic, the implant 10 may only need to reshape the annulus during a portion of the heart cycle, such as during late diastole and early systole when the heart is most full of blood at the onset of ventricular systolic contraction, when most of the mitral valve leakage occurs. For example, the implant 10 may be sized to produce small or negligible displacement of the annulus to restore or enhance inward movement of the annulus during late ventricular diastolic relaxation, as the annulus dilates and becomes restricted by the implant 10.
The mechanical force applied by the implant 10 across the left atrium can restore to the heart valve annulus and leaflets a more normal anatomic shape and tension. The more normal anatomic shape and tension are conducive to coaptation of the leaflets during late ventricular diastole and early ventricular systole, which, in turn, reduces mitral regurgitation.
In its most basic form, the implant 10 is made from a biocompatible metallic or polymer material, or a metallic or polymer material that is suitably coated, impregnated, or otherwise treated with a material to impart biocompatibility, or a combination of such materials. The material is also desirably radio-opaque or incorporates radio-opaque features to facilitate fluoroscopic visualization.
The implant 10 can be formed by bending, shaping, joining, machining, molding, or extrusion of a metallic or polymer wire form structure, which can have flexible or rigid, or inelastic or elastic mechanical properties, or combinations thereof. Alternatively, the implant 10 can be formed from metallic or polymer thread-like or suture material. Materials from which the implant 10 can be formed include stainless steel, nitinol, titanium, silicone, plated metals, eljiloy, and NP55.
The implant 10 can take various shapes and have various cross-sectional geometries. The implant 10 can have, e.g., a generally curvilinear (i.e., round or oval) cross-section, or a generally rectilinear cross section (i.e., square or rectangular), or combinations thereof.
1. The Posterior Anchoring Region
The posterior tissue anchoring region 14 is sized and configured to engage tissue within the left atrium at a supra-annular position, i.e., engaging tissue in the left atrium wall above the posterior annulus.
In the illustrated embodiment, the posterior anchoring region 14 is shown to engage tissue generally at the level of the great cardiac vein, which travels adjacent to and in parallel to the majority of the posterior mitral valve annulus. This tributary of the coronary sinus can provide a strong and reliable fluoroscopic landmark when a radiopaque device is placed within it or contrast dye is injected into it. As previously described, engagement of tissue at this supra-annular location also lessens the risk of encroachment of and risk of injury to the circumflex coronary artery compared to procedures applied to the mitral annulus directly.
The great cardiac vein also provides a site where relatively thin, non-fibrous atrial tissue can be readily augmented and consolidated. To enhance hold or purchase of the posterior tissue anchoring region 14 in what is essentially non-fibrous heart tissue, the posterior tissue anchoring region 14 can be coupled to a posterior anchor 18 placed within the great cardiac vein. This makes possible the mechanical fixation of the posterior anchoring region 14 in a non-fibrous portion of the heart in a manner that can nevertheless sustain appreciable hold or purchase on that tissue for a substantial period of time, without dehiscence, expressed in a clinically relevant timeframe.
In one embodiment (see
In this arrangement, the posterior anchor 18 can be inserted in a laid-back, collapsed condition upon the posterior anchoring region 14, through the lumen of a tissue piercing needle from the left atrium through a wall of the great cardiac vein. The posterior anchor 18 can be configured with an elastic memory such that, once free of the needle lumen, it springs open from the collapsed condition into the T-shape, to reside within the great cardiac vein. In this arrangement, the posterior anchor 18 can have a diameter of about 0.5 mm.
In the embodiment shown in
In the embodiment shown in
It should be appreciated that non-fibrous tissue at, above, or below the level of the great cardiac vein, e.g., in a range of about 5 to about 25 mm above the plane of the posterior mitral valve annulus, can be strengthened and consolidated in other ways. For example, tissue bulking agents or fibrosis caused, e.g., chemically or by heat can be used to strengthen and consolidate regions of atrial tissue above the annulus for purchase or hold by the posterior tissue anchoring region 14.
2. The Anterior Anchoring Region
The anterior anchoring region 16 is sized and configured to engage firmly the fibrous tissue and the surrounding tissues in the right atrium side of the atrial septum. This fibrous tissue region provides a tissue fixation site of better integrity than muscle in terms of devices pulling through. The septum is the most fibrous tissue structure in its own extent in the heart. Surgically handled, it is usually one of the only heart tissues into which sutures actually can be placed and can be expected to hold without pledgetts or deep grasps into muscle tissue, where the latter are required.
As
By engaging tissue at this supra-annular level within the right atrium, which is fully outside the left atrium and spaced well above the anterior annulus, the implant 10 avoids the impracticalities of endovascular attachment at or adjacent to the anterior annulus, where there is just a very thin rim of annulus tissue that is bounded anteriorly by the anterior leaflet, inferiorly by the aortic outflow tract, and medially by the atrioventricular node of the conduction system. The anterior annulus is where the non-coronary leaflet of the aortic valve attaches to the mitral annulus through the central fibrous body. Anterior fixation of the implant 10 in the supra-annular level within the right atrium (either to the septum or in a vena cava) avoids encroachment of and risk of injury to both the aortic valve and the AV node.
The purchase of the anterior tissue anchoring region 16 in fibrous septal tissue is desirably enhanced by one or more anterior anchors 20. The anterior anchor or anchors 20 mechanically amplify the hold or purchase of the anterior anchoring region 16 in the fibrous tissue site. The anterior anchor or anchors 20 also desirably increase reliance, at least partly, on neighboring anatomic structures of the septum to anchor and fix the position of the implant 10. Anticipating that pinpoint pulling forces will be applied by the anchoring region 16 to the septum, the forces acting on the anchor 20 should be spread over a moderate area, without causing impingement on valve, vessels or conduction tissues. The anchor 20 should also have a low profile configuration and highly washable surfaces to diminish thrombus formation for devices deployed inside the heart. As will be described in greater detail later, a septal brace may be used in combination with the anterior anchor or anchors 20 to distribute forces uniformly along the septum (see
Fixation of the posterior and anterior tissue anchoring regions 14 and 16 having radiopaque anchors and well demarcated fluoroscopic landmarks respectively at the supra-annular tissue sites just described, not only provides freedom from key vital structure damage—e.g., to the circumflex artery, AV node, and the left coronary and non-coronary cusps of the aortic valve—but the supra-annular fixation sites are also not reliant on purchase between tissue and direct tension-loaded penetrating/biting/holding tissue attachment mechanisms. Instead, physical structures and force distribution mechanisms like stents can be used, which better accommodate the attachment of mechanical levers and through which potential tissue tearing forces can be better distributed. Further, the fixation sites do not require the operator to use complex imaging. Adjustment of implant position after or during implantation is also facilitated, free of these constraints. The fixation sites also make possible full intra-atrial retrieval of the implant 10 by endovascularly snaring and then cutting the bridging element at either side of the left atrial wall, from which it emerges.
3. Orientation of the Spanning Region
In the embodiment shown in
Lateral or medial deviations and/or superior or inferior deviations in this path can be imparted, if desired, to affect the nature and direction of the force vector or vectors that the implant 10 applies. It should be appreciated that the spanning region or bridging element 12 can be preformed or otherwise configured with various medial/lateral and/or inferior/superior deviations to achieve targeted annulus and/or atrial structure remodeling, which takes into account the particular therapeutic needs and morphology of the patient.
For example, as shown in
Regardless of the particular location of the posterior region of anchorage (see
Various combinations of lateral/medial deviations and superior/inferior deviations of the spanning region or bridging element 12 of the implant 10 are of course possible. For example, as shown in
Regardless of the orientation, more than one implant 10 can be installed to form an implant system 22. For example,
One or both of the implants 10L and 10M can be straight (as in
B. Anchoring Elements
1. Within the Great Cardiac Vein
As before explained, the posterior tissue anchoring region 14 desirably includes one or more posterior anchors 18 placed in the great cardiac vein to enhance its purchase in supra-annular tissue in the left atrium.
The posterior anchor 18 can be variously constructed. The anchor 18 may be rigid, or flexible, or elastic, or malleable, or solid, or porous. The anchor 18 can sized and configured to provide a localized anchoring site, or be elongated and extend medially and laterally from the intended anchoring site to better consolidate atrial tissue at the level of the vein along the length of the vein.
As shown in
Alternatively, the anchor 18 can comprise a preformed, non-expandable hollow tube or solid rod of a pre-determined shape, which is sized and configured to be advanced into the great cardiac vein. Still alternatively, the anchor 18 can comprise an inert biocompatible bulking material injected into the vein, which cures to possess a desired mechanical property. Or, the anchor 18 can include a hollow structure that is at least a partially-filled with an inert biocompatible material, which cures to possess a desired mechanical property.
Regardless of the particular configuration, the anchor 18 is desirably radio-opaque or incorporates radio-opaque features to facilitate fluoroscopic visualization when positioned in a tributary of the coronary sinus.
As
2. Anchoring to Fibrous Septal Tissue
The anterior anchoring region 16 is sized and configured to pass through the septum and project into the right atrium. There, the anterior anchor 20 captures the anterior anchoring region 16 and holds the anchoring region 16 against the fibrous and surrounding muscular tissue of the septum in the right atrium.
The anterior anchor 20 can be variously constructed. In the illustrated embodiment (see, e.g.,
Alternatively, the anterior anchoring region 16 (or the entire implant 10, for that matter) can comprise suture material that is threaded through the fibrous wall of the septum, with or without the use of an anchor button or the like. In the latter case a more proximal vena caval anchor would supplant the need for using the inter-atrial septum as an anchor.
As will be described later, the anchoring site can be within either the SVC or IVC, instead of to the septum.
C. Implantation
The implants 10 or implant systems 22 as just described lend themselves to implantation in a heart valve annulus in various ways. The implants 10 or implant systems 22 can be implanted, e.g., in an open heart surgical procedure. Alternatively, the implants 10 or implant systems 22 can be implanted using catheter-based technology via a peripheral venous access site, such as in the femoral or jugular vein or femoral artery (via the IVC or SVC) under image guidance, or trans-arterial retrograde approaches to the left atrium through the aorta also under image guidance.
Alternatively, the implants 10 or implant systems 22 can be implanted using thoracoscopic means through the chest, or by means of other surgical access through the right atrium, also under image guidance.
Image guidance includes but is not limited to fluoroscopy, ultrasound, magnetic resonance, computed tomography, or combinations thereof.
Percutaneous vascular access is achieved by conventional methods into the femoral or jugular vein. As
The first catheter 26 advances the anchor 18, e.g., through the coronary sinus os in the right atrium, into the great cardiac vein above and in parallel to the posterior mitral valve annulus. A guide wire (not shown) may be used to guide the advancement. The anchor 18 is extended to a length sufficient to accommodate the desired site of fixation for the posterior anchoring region 14 of the implant 10. The length of the posterior anchor may extend from 20 mm to 200 mm as it lies inside the coronary venous system. The desired position of the posterior anchor 18 can be secured, e.g. by self-expansion or the use of a balloon to cause expansion within the vein, or it may require no conformational change from its shape inside the delivery catheter.
As
The second catheter 28 is withdrawn (
Under image guidance, the implant delivery catheter 34 is directed to a targeted posterior anchoring site at the level where the posterior anchor 18 resides within the great cardiac vein. The implant delivery catheter 34 can include an on-board distal steering mechanism, to direct the catheter 34 to the intended site with image guidance. Alternatively, or in combination (see
Once the implant delivery catheter 34 has located the targeted anchoring site (see
As
As
Regardless of the surgical manipulation and/or instrumentation used, pulling inwardly toward the left atrium on the anterior anchoring region 16 (either from within the right atrium by means of the implant delivery catheter 34 or a separate gripping tool) exerts a pulling force on posterior atrial tissue in the region where the posterior anchoring region 14 is attached to the posterior anchor 18. The pulling force draws the posterior atrial tissue inwardly toward the anterior atrial tissue of the left atrium. The existence of the elongated posterior anchor 18 serves to consolidate the length of the great cardiac vein, thereby distributing the pulling force laterally and medially. The pulling force can serve to shorten the annulus along its minor axis. The presence of the anchor 18 within the great cardiac vein consolidates the length of the great cardiac vein into a unitary physical structure, which, when pulled upon at least at one point, serves to compress the whole posterior annulus.
The physician can elect to monitor the incidence of mitral regurgitation by various conventional means, e.g., by contrast ventriculography or by echocardiographic Doppler assessment, as tension is progressively applied to the implant 12. If the physician chooses this approach, the physician can dynamically adjust tension on the implant 12 to achieve a desired diminution or elimination of the incidence or mitral regurgitation.
As
The projection of the anterior anchoring region 16 into the right atrium facilitates repositioning, retensioning, and/or retrieval of the implant 12 from the right atrium, if necessary or desired.
II. Implant Systems for Achieving Mitral Annulus UnloadingA. System Overview
The trans-septal embodiments just described with straight or linear bridging elements apply a main force vector that is directed essentially across the left atrium (i.e., at about a fifteen to less than forty-five degree vector above the horizontal) from a posterior region above the mitral valve annulus to an anterior septal tissue region, which is also above the mitral valve annulus. Use of the implant 10 or implant system 22 for this purpose can provide significant amelioration of mitral regurgitation.
Tension on the mitral valve annulus can arise when the left ventricle and annulus become dilated. The magnitude of the tension on the annulus can be significant in situations involving functional mitral regurgitation, particularly functional mitral regurgitation of at least Grade 2+. When the annulus is under tension, the mitral chordae become tense, pulling the coaptation points down and away from each other. Also the annulus-to-leaflet junction becomes taut. An analogy is midline poles (the annulus) holding up a bi-leaf tent (the leaflets), with ropes and stakes (the chordae) holding the tent leaves tautly (the taut leaflets) to the ground (the papillary muscles). If there is insufficient leaflet tissue to coapt in systole, functional mitral regurgitation is the result. This is believed to be the result of the tension that dilation places on the annulus, working in synchrony with the pulling away of the walls of the ventricle.
The implant system 40 imposes a lifting force vector on the annulus (a ventricular structure) by pulling upward on an atrial structure. To achieve this outcome, the system 40 includes a tissue consolidating component 42A, which consolidates the great cardiac vein into a unified physical structure along its length. The system 490 also includes bonding means 42B for conjoining or bonding the great cardiac vein to the ventricle in the region between the great cardiac vein and the ventricle. In this way, as the system 40 pulls upward on a consolidated great cardiac vein (an atrial structure), a lifting force vector is transferred by the conjoined great vein-ventricle tissue region upon the ventricle.
More particularly, the implant system 40 shown in
As shown in
The bonding means 42B conjoins or bonds the great cardiac vein to the ventricle in the region between the great cardiac vein and the ventricle. The means 42B bonds non-fibrous, thin atrial tissue at and below the great cardiac vein to the mitral valve annulus. The means 42B in effect bonds the component 42A that consolidates the great cardiac vein to the left ventricular muscle base proximate to the posterior mitral annulus, so that lifting and horizontal forces applied to the component 42 are directly transferred to lifting and/or compression of the annulus itself. The means 42B also diminishes the possibility of a Type 1 left ventricular rupture between the great cardiac vein and the top of the left ventricle as a result of the forces applied to the component 42 over time.
The means 42B for bonding of the great cardiac vein to the ventricle can take various forms. Mechanical means, such as staples can be attached between the component 42A and tissue in the left ventricle. Drugs, and/or irritative agents, and/or heat (e.g., radiofrequency heating), and/or chemical agents can be applied to tissue in the region. Alternatively, or in combination, tissue at or near the great cardiac vein can be subject to fibrosis to reinforce the tissue and elevate the pull-through threshold of the component 42A. Fibrosis can be accomplished by the use of polyester coatings, drugs, irritative agent elutions, or combinations thereof. Fibrosis can also be achieved by the application of heat.
As shown in
In the illustrated embodiment, the elements 222 are carried for implantation by expandable or inflatable bodies 224, e.g., balloons. The bodies 224 can be individually placed by deployment of a catheter through the aortic valve into the left ventricle, into spaced apart locations under the posterior leaflet. Once implanted, the bodies 244 can be expanded or inflated to stabilize the position of the elements 222, e.g., by injection of saline. The magnetically attraction between the magnets 220 and elements 222 draws the two tissue region together, thereby bonding the great cardiac vein to the posterior annulus.
As shown in
As
The lifting component 44 also includes an anterior anchoring region 50 that passes out of the left atrium and into the right atrium through fibrous tissue of the high septum. In
The lifting component 44 can be formed by bending, shaping, joining, machining, molding, or extrusion of a metallic or polymer wire form structure, which can have flexible or rigid, or inelastic or elastic mechanical properties. The lifting component 44 can take various shapes and have various cross-sectional geometries. The lifting component can have, e.g., a generally curvilinear (i.e., round or oval) cross-section, or a generally rectilinear cross section (i.e., square or rectangular), or combinations thereof.
Desirably, the lifting component 44 is “elastic.” The lifting component 44 is sized and configured to possess a normal, unloaded, shape or condition, in which the component is not in compression or tension. The material of the lifting component 44 is selected to possess a desired spring constant. The spring constant imparts to the component 44 the ability to be elastically stretched and placed in tension in response to external pulling applied at the anterior anchoring region 50 when the posterior anchoring region 46 is coupled to the tissue consolidating component 42A. When in tension, the lifting component 44 applies an upward force (e.g., with a force vector of great than about 45° above horizontal) upon the tissue-consolidating component 42A.
The system 40 further comprises an anchor 52 sized and configured to be coupled to the anterior anchoring region 50 of the lifting component 44 in the right heart. The anchor 52 holds the lifting component 44 in tension against the septum in the right atrium. In an alternative embodiment, stents or equivalent non-obstructing anchors in the IVC or SVC can serve as anchoring sites for the lifting component or components 44.
The lifting component and anchoring component desirably incorporates radio-opaque features to facilitate fluoroscopic visualization.
As
The arched lifting components 44, which elevate a consolidated great cardiac vein vertically, while bringing it horizontally inward toward the septum, provide mural support to the wall of the left atrial chamber.
The components of the system 40, when assembled in the manner shown in
As the ventricle starts to fill with blood, the spring-like lifting component 44 or components become maximally loaded at end-diastole and in early systole, when the mitral valve area is the least and functional mitral regurgitation is most likely to occur. The spring energy unloads the ventricular muscular wall tension at end-diastole and early systole, and the annulus is relieved of tension (at least partially) enough to release or dissipate tension from tented mitral leaflets, thereby allowing improved re-approximation of the mitral leaflets especially in late diastole and early systole to allow closure.
The system 40 may also, as a primary or secondary effect, result in re-shaping the annulus.
As
The auxiliary implant components 60 can be made—e.g., by bending, shaping, joining, machining, molding, or extrusion—from a biocompatible metallic or polymer material, or a metallic or polymer material that is suitably coated, impregnated, or otherwise treated with a material to impart biocompatibility, or a combination of such materials. The material is also desirably radio-opaque or incorporates radio-opaque features to facilitate fluoroscopic visualization. The auxiliary implant components desirable include struts that engage supra-annular tissue.
Further details of implants that can be used as auxiliary implant components 60 are shown in co-pending U.S. patent application Ser. No. 10/677,104, filed Oct. 1, 2003, and entitled “Devices, Systems, and Methods for Reshaping a Heart Valve Annulus,” which is incorporated herein by reference.
B. Implantation
The implant systems 40 as just described lend themselves to implantation in a left and right heart in various ways. The systems can be implanted, e.g., in an open heart surgical procedure. Alternatively, the systems can be implanted using catheter-based technology via a peripheral venous access site, such as in the femoral, jugular, subclavian vein or femoral artery, under image guidance.
Alternatively, the systems 40 can be implanted using thoracoscopic means through the chest, or by means of other surgical access through the right atrium, also under image guidance. Image guidance includes but is not limited to fluoroscopy, ultrasound, magnetic resonance, computed tomography, or combinations thereof.
It is believed that the implant system 40 as described can be sized and configured to allow leaflets to coapt in the face of functional mitral regurgitation above Grade 1+, including up to Grade 4+, which could be ameliorated at least to some significant extent. The system provides rapid deployment, facile endovascular delivery, and full intra-atrial retrievability. The system also provides strong fluoroscopic landmarks.
III. Right Heart BracingAs
A. Right Atrial Septal Brace
In embodiment shown in
As
B. Vena Caval Anchoring
As
In the embodiment shown in
In the embodiment shown in
C. Implantation
The right heart components 54 described above lend themselves to implantation in any of the manners previously described.
In a representative catheter-based embodiment, the tissue-consolidating component 42 (which can comprise, e.g., a rigid, malleable, radiopaque-marked stent dilated to 10 mm to 25 mm in diameter) can be placed by a catheter into the great cardiac vein, as before described. If the bracing stent 58 is intended to rest in the IVC, a femoral vein into the IVC route can be used. If the bracing stent 58 is intended to rest in the SVC, then a jugular vein into the SVC route is selected.
A guide sheath is then placed through a femoral vein-IVC-fossa ovalis route across the left atrium to the tissue-consolidating component 42. The element 202 is passed through the guide sheath. The element 202 carries at its distal end a grasper (which can be sized, e.g., 7 French). The grasper grasps onto a strut of the tissue consolidating stent 42 and locks that grasp. The element 202 is then drawn across the left atrium, through the fossa ovalis. Tension is applied from within the right atrium to pull the tissue-consolidating stent 42 up and in inside the left atrium. The tension is set to moderate or eliminate the functional MR as much as possible.
The caval stent 58 (e.g., measuring 5 cm to 10 cm long, and 3 cm to 7 cm diameter) is threaded over the element 202 into the vena cava where catheter access for the element 202 was achieved. In the IVC, for example, the stent 58 gets placed just above the liver and just below the right atrium. A lock device is threaded over the element 202 from its proximal end up to the caval stent 58. The element 202 is then cut below the lock nut and the element 202 below the nut is removed. The stent 58 serves to hold and lock the element 202 in its vertical position.
It is believed that providing the option of using either the atrial septum, and/or the IVC, and/or the SVC as potential anchoring sites in the manners just described, makes it possible to flexibly adapt a given implant system to the local anatomy encountered, as well as to optimally guide and distribute the direction and magnitude of the force vectors sought to be applied by the intra-atrial bridging component or components.
III. Circumferential Implant SystemsA. Circumferential Loop
1. Structure
As shown in
As shown in
The loop implant 70 serves to apply a direct mechanical force that pulls radially inward upon the posterior annulus. The direct mechanical force can serve to shorten the minor axis of the annulus. In doing so, the implant 70 can also reactively reshape the annulus along its major axis and/or reactively reshape other surrounding anatomic structures. It should be appreciated, however, the presence of the implant 70 can serve to stabilize tissue adjacent the heart valve annulus, especially at different and important times in the cardiac cycle when valve coaptation should be improved (e.g., late diastole and early systole), without affecting the length of the minor or major axes. The mechanical force applied by the implant 70 to the tissues attached to the annulus can restore to the heart valve annulus and leaflets a more normal anatomic shape and tension, conducive to coaptation of the leaflets during ventricular systole. The implant 70 can thus reduce the incidence of mitral regurgitation.
Due to the superior location of the anchor 80 in the septum in the illustrated embodiment, the mechanical force of the loop implant 70 also pulls upward (i.e., with a vertical force vector) on the posterior annulus. This vertical vector is further enhanced when anchorage originates in the superior vena cava and a more vertical pull is exerted on the bridging element or bridge from this vantage than can be from a septal anchor. This vertical force vector can also serve to unload tension on the annulus, as well as to lessen the horizontal leading length of atrial tissue between the GCV and the ventricle, which must be moved by an anchor in the GCV in order to achieve any compressive effect on the posterior annulus, with the beneficial effects previously described. In situations where the SVC orifice is high enough, the magnitude of the vertical vector can be enhanced if the right side bridging element is anchored to a stent in the SVC in the manner shown in
In its most basic form, the implant 70 is made from a biocompatible metallic or polymer material, or a metallic or polymer material that is suitably coated, impregnated, or otherwise treated with a material to impart biocompatibility, or a combination of such materials. The material is also desirably radio-opaque or incorporates radio-opaque features to facilitate fluoroscopic visualization.
As shown in the illustrated embodiment, the portion of the intermediate region 78 that resides within the great cardiac vein can comprise a stent-like structure that is sized and configured to be introduced into the great cardiac vein through the coronary sinus os in the right atrium. In this form, the intermediate region 78 can comprise an expandable scaffold, which can take the form of a self-expanding stent, or a malleable structure that is expanded by means of an interior force, e.g., a balloon. The intermediate region 78 may be held in position within the vein by gripping the surrounding vessel wall, e.g., by barbs, tines, or the like. If desired, the intermediate region 78 may be further secured by suture, adhesive, or like material within the vein. The intermediate region 78 can incorporate roughened or porous surfaces and/or other materials (e.g., polyester fabric) to promote tissue in-growth.
The anchoring regions 74 and 76 can comprise wire-form structures formed by bending, shaping, joining, machining, molding, or extrusion of a metallic or polymer wire form structure to the intermediate region 78. Desirably, the material of the implant 70 is selected to impart elastic mechanical properties.
2. Implantation
The loop implant 70, like the implant or implant systems already described, lends itself to implantation in a heart valve annulus in a beating heart or an open heart surgical procedure, or by catheter-based technology via a peripheral venous access site under image guidance, or by closed chest thoracoscopic means through the chest, or by means of other open chest surgical access through the right atrium under image guidance.
For example, if a percutaneous, catheter-based procedure is used under image guidance, percutaneous vascular access can be achieved by conventional methods into the femoral or jugular or subclavian vein to deploy a first catheter 82 into the right atrium. As shown in
As
The second catheter 84 is withdrawn (see
The first catheter 82 and the third catheter 86 are manipulated within the right atrium to pull tension on the implant 70, until a lessening or elimination of the incidence of mitral regurgitation is confirmed by monitoring. Once the desired therapeutic result is achieved, the anchor 80 is applied to both anchoring regions 74 and 76, e.g., by one of the catheters 82 or 86 or by a separate intravascular crimping tool or a lock that is advanced from the outside over the wire to engage the brace. This retains the loop implant 70 in the desired degree of tension. The anchoring region 74 is cut next to anchor 80, ending the installation, and the intravascular tool or tools are withdrawn, leaving the implant 70 in the condition shown in
B. Loop Systems
In an alternative embodiment (see
The implant system 90 also includes a tension element 96. The tension element 96 has anchoring end regions 98 and 100 and an intermediate region 102. The tension element 96 can comprise a wire-form structure formed by bending, shaping, joining, machining, molding, or extrusion of a metallic or polymer wire form structure. Desirably, the material of the element 96 is selected to impart elastic mechanical properties.
In use, as
Held in tension by the anchors 100, the intermediate region 102 of the element 96 extends within the right atrium from the end region 98, into the great cardiac vein through the coronary sinus, passes through the lumen 94 of the shaped structure 92 within the great cardiac vein, exits the great cardiac vein at or near the lateral trigone (or at any point thought to best achieve a maximal effect on the annulus to ameliorate functional mitral regurgitation—i.e., at or near the mid point of the posterior mitral annulus), and, from there, spans in a posterior-to-anterior path across the left atrium to the anchoring element 100.
Like the loop implant 70 shown in
As previously explained in connection with the implant 70, the anchors 104 can be placed relatively high in the septum (e.g., at the fossa ovalis) to apply a mechanical force that also pulls upward (i.e., with a vertical force vector) on the posterior annulus. This vertical force vector can also serve to unload tension on the annulus, as well as to lessen the horizontal leading length of atrial tissue between the great cardiac vein and the ventricle, which must be moved by an anchor in the great cardiac vein into order to achieve a compressive effect on the posterior annulus. Alternatively, the implant can be anchored directly either to the SVC (in the manner shown in
Similar tools and techniques as previously described can be used to implant the system 90 shown in
A. Elastic Right Heart Implant
In terms of structure, the right heart implant 120 can be of the type described in copending U.S. patent application Ser. No. 10/677,104, filed Oct. 1, 2003, and entitled “Devices, Systems, and Methods for Reshaping a Heart Valve Annulus,” which is incorporated herein by reference—except that, in use, the implant 120 is intended, in use, to be implanted in the right heart and not the left heart, as disclosed in the referenced application.
As described in the above-identified application, the implant 120 is desirably made—e.g., by bending, shaping, joining, machining, molding, or extrusion—from a biocompatible, super-elastic metallic material. As shown in
As
The superelastic material of the right heart implant 120 is selected to possess a desired spring constant. The spring constant imparts to the rail 126 the ability to be elastically compressed into an elastically loaded condition, when resting in engagement with tissue as just described. When in its elastically loaded, compressed condition, the rail 126 exerts opposing forces to the tissues through the struts 122 and 124.
The struts 122 and 124 can engage tissue in a stable fashion in various ways. The struts 122 and 124 can rely upon compressive forces imparted by the mechanical, superelastic properties of the rail 126 to retain a stable position engaged in tissue. The struts 122 and 124 can, alternatively or in combination with compressive forces, include barbs or other fixation devices that penetrate or otherwise take purchase in tissue. Other types of tissue engaging mechanisms can be used, e.g., roughened surfaces or tissue in-growth promoting materials. Any fixation mechanism may, if desired, be combined with suture, an adhesive, or like material to further secure the right heart implant 120.
The compression force applied by the septal strut 122 applies a force on the septum in the direction of the left atrium (a shown by arrows in
The right heart implant 120 can be elastically straightened and/or folded to fit within a catheter or sheath for deployment in a catheter-based procedure within the right atrium. Alternatively, the right heart implant 120 can be deployed during an open surgical or thoracoscopic procedure.
B. Plastically Deformable Right Heart Implant
As shown in
The frame 132 is sized and configured to rest in tissue in, at, or near the septum in the right atrium at a location that is generally in opposition to a portion of the anterior annulus of the mitral valve in the left atrium.
The implant 130 also includes an array of tissue fixation elements 134, which are attached to the periphery of the frame 132. In the illustrated embodiment, the fixation elements 134 comprise barbs that penetrate tissue, to secure the frame 132 to the targeted tissue region. Other types of tissue engaging mechanisms can be used, e.g., roughened surfaces or tissue in-growth promoting materials. Any fixation mechanism may, if desired, be combined with suture, an adhesive, or like material to further secure the frame 132 of the right heart implant 130.
A plastically deformable structure 136 is mounted to the interior of the frame 132. In the illustrated embodiment, the structure 136 takes the form of a woven or mesh-like web, which can be made of a metallic or polymeric material. The structure 136 is attached to the frame 130 in a normally unstretched condition. In is in this condition that the implant 130 is affixed to the targeted tissue region on the septum (see
The plastically deformable nature of the structure 136 makes possible its expansion and shaping in situ against the septum within the right atrium. As
During expansion and shaping, the structure 136 is stretched into an outwardly bowed or concave configuration within the frame 130. The stretched structure 132 projects against the septum (see
The mechanical force applied by the right heart implant 130 across the septum may restore to the mitral valve annulus and leaflets a more normal anatomic shape and tension. The more normal anatomic shape and tension are conducive to coaptation of the leaflets during ventricular systole, which, in turn, reduces mitral regurgitation.
The plastically deformable implant 130 shown in
C. Right Heart Anchored Great Cardiac Vein Implant
In preceding embodiments (see, e.g.,
As
As
It should by now be apparent that the features and concepts disclosed herein can be used, alone or in combination, to create implants or systems of implants that apply a selected force vector or a selected combination of force vectors, which allow mitral valve leaflets to better coapt. The features and concepts make possible rapid deployment, facile endovascular delivery, and full intra-atrial retrievability. The features and concepts also make use of strong fluoroscopic landmarks.
While the new devices and methods have been more specifically described in the context of the treatment of a mitral heart valve, it should be understood that other heart valve types can be treated in the same or equivalent fashion. By way of example, and not by limitation, the present systems and methods could be used to prevent or reduce retrograde flow in any heart valve annulus, including the tricuspid valve, the pulmonary valve, or the aortic valve. In addition, other embodiments and uses of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. The specification and examples should be considered exemplary and merely descriptive of key technical; features and principles, and are not meant to be limiting. The true scope and spirit of the invention are defined by the following claims. As will be easily understood by those of ordinary skill in the art, variations and modifications of each of the disclosed embodiments can be easily made within the scope of this invention as defined by the following claims.
Claims
1. An implant system to treat a mitral heart valve comprising
- a posterior anchor structure sized and configured to extend within the great cardiac vein,
- at least one implant sized and configured to extend across a left atrium, said at least one implant including:
- a bridging implant member having:
- a posterior anchoring region sized and configured to extend from the left atrium into the great cardiac vein and couple to the posterior anchor structure within the great cardiac vein,
- an anterior anchoring region sized and configured to extend from the left atrium through an interatrial septum and into a right atrium, and
- a bridging region between the posterior and anterior anchoring regions sized and configured to span the left atrium; and
- an anterior anchor sized and configured to couple to the anterior anchoring region in or near the right atrium to hold in tension the bridging element between the posterior and anterior anchoring regions.
2. The implant system according to claim 1
- wherein said bridging implant member is a wire form structure.
3. The implant structure according to claim 2
- wherein the said wire form structure comprises a suture material.
4. An implant system according to claim 1
- wherein the posterior anchor structure comprises a structure separate from the implant to which the posterior anchoring region is joined.
5. An implant system according to claim 1
- wherein the posterior anchor structure comprises a structure integrally joined to the posterior anchoring region.
6. An implant system according to claim 1
- wherein the posterior anchor structure comprises a stent-like structure.
7. An implant system according to claim 1
- wherein the posterior anchor structure comprises, at least in part, a radiopaque structure.
8. An implant system according to claim 1
- wherein the posterior anchor structure includes a magnetic or ferromagnetic material.
9. An implant system according to claim 1
- wherein the posterior anchor structure includes at least one anchoring site sized and configured to accommodate attachment of the posterior anchoring region.
10. An implant system according to claim 9
- wherein the at least one anchoring site includes a magnetic or ferromagnetic material.
11. An implant system according to claim 1
- wherein the posterior anchor structure includes at least one anchoring site sized and configured to accommodate attachment of the posterior anchoring region, and a region extending either medially from the anchoring site, or laterally from the anchoring site, or both medially or laterally from the anchoring site.
12. An implant system according to claim 1
- wherein the posterior anchor structure comprises a material selected from the group consisting of a rigid material, or a semi-rigid material, or a flexible material, or a porous material, or combinations thereof.
13. An implant system according to claim 1
- wherein the posterior anchor structure includes one or more components to engage tissue within the great cardiac vein.
14. An implant system according to claim 1
- wherein the posterior anchoring region includes means for mechanically engaging at least a portion of the posterior anchoring structure within the great cardiac vein.
15. An implant system according to claim 1
- wherein the posterior anchoring region includes a cross-bar structure for engaging at least a portion of the posterior anchoring structure within the great cardiac vein.
16. An implant system according to claim 1
- wherein the posterior anchoring region includes a magnetic or ferromagnetic material.
17. An implant system according to claim 1
- wherein the posterior anchor structure includes at least one anchoring site sized and configured to accommodate attachment of the posterior anchoring region, the at least one anchoring site including a material magnetically attracted to the magnetic or ferromagnetic material on the posterior anchoring region.
18. An implant system according to claim 1
- wherein the anterior anchoring structure is sized and configured for attachment on the interatrial septum.
19. An implant system according to claim 1
- wherein the anterior anchoring structure is sized and configured for attachment on the interatrial septum in a region at or near of the fossa ovalis.
20. An implant system according to claim 1
- wherein the anterior anchoring structure is sized and configured for attachment within the superior vena cava, and further including a pass-through element on the interatrial septum through which the anterior anchoring region extends without anchoring to the interatrial septum.
21. An implant system according to claim 1
- wherein the anterior anchoring structure is sized and configured for attachment within the inferior vena cava, and further including a pass-through element on the interatrial septum through which the anterior anchoring region extends without anchoring to the interatrial septum.
22. An implant system according to claim 1
- wherein the anterior anchoring structure is sized and configured for attachment within the inferior vena cava and the superior vena cava, and further including a pass-through element on the interatrial septum through which the anterior anchoring region extends without anchoring to the interatrial septum.
23. An implant system according to claim 1
- wherein the bridging region is collapsible for placement within a catheter.
24. An implant system according to claim 1
- wherein the posterior anchor structure is collapsible for placement within a catheter.
Type: Application
Filed: Feb 17, 2015
Publication Date: Jun 11, 2015
Applicant: MVRx, INC. (MOSS BEACH, CA)
Inventors: JOHN A. MACOVIAK (LA JOLLA, CA), ROBERT T. CHANG (BELMONT, CA), DAVID A. RAHDERT (SAN FRANCISCO, CA), TIMOTHY R. MACHOLD (MOSS BEACH, CA)
Application Number: 14/624,131