Methods and devices for improving mitral valve function
The various aspects of the invention pertain to devices and related methods for treating heart conditions, including, for example, dilatation, valve incompetencies, including mitral valve leakage, and other similar heart failure conditions. The devices and related methods of the present invention operate to assist in the apposition of heart valve leaflets to improve valve function. According to one aspect of the invention, a method improves the function of a valve of a heart by placing an elongate member transverse a heart chamber so that each end of the elongate member extends through a wall of the heart, and placing first and second anchoring members external the chamber. The first and second anchoring members are attached to first and second ends of the elongate member to fix the elongate member in a position across the chamber so as to reposition papillary muscles within the chamber. Also described herein is a method for placing a splint assembly transverse a heart chamber by advancing an elongate member through vasculature structure and into the heart chamber.
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This is a continuation of application Ser. No. 10/762,513 filed Jan. 23, 2004 of Richard SCHROEDER et al. for METHODS AND DEVICES FOR IMPROVING MITRAL VALVE FUNCTION, which is a continuation of application Ser. No. 09/680,435 filed Oct. 6, 2000, now U.S. Pat. No. 6,723,038 of Richard SCHROEDER et al. for METHODS AND DEVICES FOR IMPROVING MITRAL VALVE FUNCTION, the complete disclosures of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION1. Field of the Invention
The present invention relates to devices and related methods for improving the function of heart valves, and more particularly to devices and related methods that passively assist in the apposition of heart valve leaflets to improve valve function of poorly functioning valves.
2. Description of the Related Art
Heart failure is a condition whereby the left ventricle becomes enlarged and dilated as a result of numerous etiologies. Initial causes of heart failure include chronic hypertension, myocardial infarction, mitral valve incompetency, and other dilated cardiomyopathies. With each of these conditions, the heart is forced to overexert itself in order to provide the cardiac output demanded from the body during its various demand states. The result is an enlarged left ventricle.
A dilated heart, and particularly a dilated left ventricle, can significantly increase the tension and/or stress in the heart wall both during diastolic filling and systolic contraction, which contributes to ongoing dilatation of the chamber. Prior treatments for heart failure include pharmacological treatments, assist devices such as pumps, and surgical treatments such as heart transplant, dynamic cardiomyoplasty, and the Batista partial left ventriculectomy. These prior treatments are described briefly in U.S. Pat. No. 5,961,440 to Schweich, Jr. et al., issued Oct. 5, 1999 and entitled “Heart Wall Tension Reduction Apparatus and Method,” the complete disclosure of which is incorporated by reference herein.
A more recent concept for treating heart failure applies one or more splints onto the heart, and particulary the left ventricle, to reduce the myocardial muscular stresses encountered during pumping. Many examples of such approaches are disclosed in the incorporated U.S. Pat. No. 5,961,440. One example includes one or more transventricular splints placed across the left ventricle. Each splint may include a tension member extending across the ventricle and anchors disposed on opposite ends of the tension member and placed on the external surface of the heart.
Mitral valve incompetency or mitral valve regurgitation is a common comorbidity of congestive heart failure. As the dilation of the ventricle proceeds, valve function may worsen. The resultant volume overload condition, in turn, increases ventricular wall stress thereby advancing the dilation process, which may further worsen valve dysfunction.
In heart failure, the size of the valve annulus (particularly the mitral valve annulus) increases while the area of the leaflets of the valve remains constant. This may lead to an area of less coaptation of the valve leaflets, and, as a result, eventually to valve leakage. Moreover, in normal hearts, the annular size contracts during systole, aiding in valve coaptation. In heart failure, there is poor ventricular function and elevated wall stress. These effects tend to reduce annular contraction and distort annular size, often exacerbating mitral valve regurgitation. In addition, as the chamber dilates, the papillary muscles (to which the leaflets are connected via the chordae tendonae) may move radially outward and downward relative to the valve, and relative to their normal positions. During this movement of the papillary muscles, however, the various chordae lengths remain substantially constant, which limits the full closure ability of the leaflets by exerting tension prematurely on the leaflets. This condition is commonly referred to as “chordal tethering.” The combination of annular changes and papillary changes results in a poorly functioning valve.
It has been observed that for at least certain placements, or orientations, of the one or more transventricular splints in humans, a pre-existing mitral valve incompetency can be exacerbated by the presence and impact of the tightened splints. The splints and the local deformation they impart may further alter the positions of the papillary muscles in such a way that the chordae do not allow as complete of a closure of the mitral valve, or that rotation of portions of the ventricular wall (to which additional chordae may be attached) may “tighten” one valve leaflet and “loosen” the other. In this manner, the leaflets may not close at the same level relative to the annulus, causing increased retrograde leakage through the valve.
Even in instances where the placement of splints does not contribute to further mitral valve leakage, it may be desirable to provide a therapy which could also correct the valve incompetency. A heart with even a small amount of regurgitation may benefit from not only the stress reducing functions of the ventricular splints as described above, but also from the elimination of the regurgitation, which will further off-load the pumping requirements of the myocardium.
While currently available methods of mitral valve repair or replacement are possible to employ in conjunction with ventricular splinting, they typically require opening the heart to gain direct access to the valve and its annulus. This type of access necessitates the use of cardiopulmonary bypass, which can introduce additional complications to the surgical procedure. Since the implantation of the splints themselves do not require the patient to be on cardiopulmonary bypass, it would be advantageous to devise a technique which could improve the mitral valve without the need for cardiopulmonary bypass. The ability to improve the mitral valve function without the need for cardiopulmonary bypass would began advantage, both in conjunction with ventricular splinting, and also as a stand-alone therapy.
SUMMARY OF THE INVENTIONObjects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. To achieve the objects and in accordance with the purpose of the invention, as embodied and broadly described herein, one aspect of the invention comprises a method for improving the function of a valve of a heart. The method includes the steps of placing an elongate member transverse a heart chamber so that each end of the elongate member extends through a wall of the heart, and placing first and second anchoring members external to the chamber. The first and second anchoring members are attached to first and second ends of the elongate member to fix the elongate member in a position across the chamber so as to reposition papillary muscles within the chamber.
According to another aspect, the invention comprises a method for improving the function of a valve of a heart. The method includes the steps of placing an elongate member transverse a heart chamber so that a first end of the elongate member extends through a wall of the heart between two papillary muscles, and a second end of the elongate member extends through a septum of the heart; placing a first anchoring member external the heart; and placing a second anchoring member inside the heart adjacent the septum. The first and second anchoring members are attached to the first and second ends of the elongate member respectively to fix the elongate member in a position across the heart chamber.
According to a further aspect, the invention comprises a method for improving the function of a valve of a heart. The method includes the steps of placing an elongate member transverse a heart chamber so that each end of the elongate member extends through a wall of the heart; and placing first and second anchoring members external the chamber. The first and second anchoring members are attached to the ends of the elongate member to fix the elongate member in a position across the chamber. The position is superior to the papillary muscles and proximate and substantially across the valve.
According to an even further aspect, the invention comprises a splint for improving the function of a valve of a heart. The splint includes an elongate member configured to be positioned transverse a heart chamber so that each end of the elongate member extends through a wall of the heart, and first and second anchoring members configured to be positioned external the chamber and attached to the ends of the elongate member to fix the elongate member in a position across the chamber. The first anchoring member includes a first portion configured to contact a first region of the heart proximate the valve to change a shape of the valve. Preferably, the first portion will contact a first region of the heart proximate the valve annulus to change the shape of the valve annulus.
According to another aspect, the invention comprises a splint for improving the function of a valve of a heart. The splint includes an elongate member configured to be positioned transverse a heart chamber so that each end of the elongate member extends through a wall of the heart, first and second anchoring members configured to be positioned external the chamber and attached to the ends of the elongate member to fix the elongate member in a position across the chamber, a third anchoring member connected to at least one of the first and second anchoring members by a connection member. The third anchoring member is configured to contact a region of the heart proximate the valve to change a shape of the valve.
According to a further aspect, the invention comprises a device for improving the function of a valve of a heart. The device includes a first splint having a first elongate member configured to be positioned transverse a heart chamber so that each end of the elongate member extends through a wall of the heart, and a first anchoring member configured to be positioned external the chamber and attached to a first end of the first elongate member. The device further includes a second splint having a second elongate member configured to be positioned transverse a heart chamber so that each end of the second elongate member extends through a wall of the heart, and a second anchoring member configured to be positioned external the chamber and attached to a first end of the second elongate member. The device also includes a connecting mechanism configured to be connected to the second ends of each of the first and second elongate members external the chamber and press the wall of the heart chamber to change a shape of the valve.
Yet a further aspect of the invention includes a method for improving cardiac function, comprising placing a first member relative to a heart chamber to alter the cross-sectional shape of the chamber and placing a second member relative to a valve of the heart chamber to assist in apposition of leaflets of the valve.
According to an even further aspect, the invention includes a method of improving the function of a valve of a heart comprising applying a force to an exterior surface of a wall surrounding a chamber of the heart substantially at a location of the valve to alter a shape of the valve.
Yet a further aspect of the invention includes a method for improving the function of a valve of a heart comprising placing a device relative to the heart to alter a shape of the valve and adjusting the device relative to the heart based on data obtained during the adjusting from real-time monitoring of valve function.
Another aspect of the present invention pertains to splint devices, and related splinting methods, for endovascular implantation on the heart. The splints of the present invention may be implanted endovascularly through remote vascular access sites. The inventive techniques and devices thus are minimally invasive and less risky to patients.
According to an aspect of the invention, a method for placing a splint assembly transverse a heart chamber comprises providing an elongate member having a first end and a second end and a deployable heart-engaging assembly connected to at least the first end. The method further includes advancing the elongate member through vasculature structure and into the heart chamber such that the first end of the elongate member extends through a first location of a wall surrounding the heart chamber and the second end extends through a second location of the heart chamber wall substantially opposite the first location. A deployable heart-engaging assembly is deployed such that it engages with a first exterior surface portion of the heart chamber wall adjacent the first location. The elongate member is secured with respect to the heart with a second heart-engaging assembly connected to the second end. The second heart-engaging assembly engages with a second exterior surface portion of the heart chamber wall adjacent the second location.
Another aspect of the invention includes a splint assembly for treating a heart, comprising an elongate member configured to extend transverse a chamber of the heart and at least one heart-engaging assembly formed at least partially from portions forming the elongate member. The heart-engaging assembly has a collapsed configuration adapted to travel through a heart wall and an expanded configuration adapted to engage the heart wall.
Yet another aspect of the invention includes a delivery tool for delivering a transventricular splint assembly to a chamber of the heart, comprising a tubular member having a distal end and a proximal end, the distal end having a curved configuration and the tube defining a lumen configured to carry at least a portion of the splint assembly. The delivery tool further includes at least one support mechanism disposed proximate the distal end of the tubular member, the support mechanism being configured to stabilize the tubular member with respect to a heart wall surrounding the chamber. The tubular member is configured to be advanced through vasculature structure and into the heart chamber.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
BRIEF DESCRIPTION OF THE DRAWINGSThe accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention and together with the description, serve to explain the principles of the invention.
The various aspects of the invention to be discussed 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 device of the present invention preferably operates passively in that, once placed in the heart, it does not require an active stimulus, either mechanical, electrical, or otherwise, to function. Implanting one or more of the devices of the present invention 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.
The inventive devices and related methods 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 surgical techniques and tools for implanting the devices of the present invention do not require the invasive procedures of current surgical techniques. For instance, the surgical technique does not require removing portions of the heart tissue, nor does it necessarily require opening the heart chamber or stopping the heart during operation. For these reasons, the surgical techniques for implanting the devices of the present invention also are less risky to the patient than other techniques. The less invasive nature of the surgical techniques and tools of the present invention may also allow for earlier intervention in patients with heart failure and/or valve incompetencies.
The disclosed inventive devices and related methods involve geometric reshaping of the heart and treating valve incompetencies. In certain aspects of the inventive devices and related methods, substantially the entire chamber geometry is altered to return the heart to a more normal state of stress. Models of this geometric reshaping, which includes a reduction in radius of curvature of the chamber walls, can be found in U.S. Pat. No. 5,961,440 incorporated above. Prior to reshaping the chamber geometry, the heart walls experience high stress due to a combination of both the relatively large increased diameter of the chamber and the thinning of the chamber wall. Filling pressures and systolic pressures are typically high as well, further increasing wall stress. Geometric reshaping according to the present invention reduces the stress in the walls of the heart chamber to increase the heart's pumping efficiency, as well as to stop further dilatation of the heart.
Although many of the methods and devices are discussed below in connection with their use in the left ventricle and for the mitral valve of the heart, these methods and devices may be used in other chambers and 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 in other chambers and for other valves of the heart. The left ventricle and the mitral valve have been selected for illustrative purposes because a large number of the disorders that the present invention treats occur in the left ventricle and in connection with the mitral valve. It also is contemplated that the inventive endovascular splinting devices and methods will be used to support an infarcted heart wall to prevent further dilatation, or to treat aneurysms in the heart. U.S. application Ser. No. 09/422,328, filed on Oct. 21, 1999, entitled “Methods and Devices for Improving Cardiac Function in Hearts,” now issued as U.S. Pat. No. 6,406,420, which is assigned to the same assignee as the present application and is incorporated by reference herein, discusses this form of heart failure in more detail. Furthermore, 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 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.
Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
A currently preferred orientation of transventricular splints for lessening myocardial muscular stresses is shown in
In the preferred orienation shown in
Each splint includes a tension member 16 and an anchor assembly 18 at each end of the tension member 16. Presently preferred embodiments of tension members 16, anchor assemblies 18, and their connection to one another are disclosed in the '049 application incorporated by reference above. As shown in
As mentioned above, human implantations of splints, including in an orientation shown in
The orientation of splints 14 shown in
Various methods may be employed to implant the splints 14 in the orientaion shown in
Because the lower two splints 14 are positioned at an angle, they tend to “lift” one or both papillary muscles PM as they impart shape change to the left ventricle LV. By lifting the papillary muscle(s) PM, some slack may be provided to the chordae connected to the valve leaflets to permit improved apposition of the leaflets of mitral valve MV. It is contemplated that more or less splints than the lower two splints may be angled (other than perpendicularly) relative to the ventricular axis to achieve the benefits to MVR, and that each splint may have a different angle relative to that axis. For example, all three splints could be angled, or only one splint could be angled. The number of splints to be angled, and the degree of such angles, would be chosen to optimize the improvement in MVR and would depend on factors such as the particular anatomy of a heart. The splint positioning can be iteratively changed and the impact on MVR, and mitral valve function in general, can be monitored using appropriate “real-time” imaging techniques and equipment, such as, for example, ultrasound and other suitable mechanisms. The ventricular splints 14 shown in
According to an embodiment of the present invention, a method of improving mitral valve function, while maintaining the positions and orientations of the ventricular splints shown in
The MV splint 20 improves mitral valve function through a combination of effects. First, the shape of the annulus is directly altered, preferably during the entire cardiac cycle, thereby reducing the annular cross sectional area and bringing the posterior leaflet in closer apposition to the anterior leaflet. Second, the position and rotational configuration of the papillary muscles PM and surrounding areas of the left ventricle LV are further altered by the tightening of the MV splint 20. This places the chordae in a more favorable state of tension, allowing the leaflets to more fully appose each other. Third, since the annulus of the valve is muscular and actively contracts during systole, changing the shape of the annulus will also reduce the radius of curvature of at least portions of the annulus, just as the shape change induced by the ventricular splints reduces the radius of at least significant portions of the ventricle. This shape change and radius reduction of the annulus causes off-loading of some of the wall stress on the annulus. This, in turn, assists the annulus's ability to contract to a smaller size, thereby facilitating full closure of the mitral valve MV during systole.
The position of the MV splint-20 shown in
It is anticipated that the optimal position of the MV splint 20 could be at virtually any orientation relative to the valve leaflets, depending on the heart failure and mitral valve regurgitation associated with the particular heart at issue. For example, in some hearts, the position shown and described in connection with
According to another embodiment of the present invention, an alternative anchor assembly for the ventricular splints 14 may be provided to aid in mitral valve function. In the embodiment shown in
In the exemplary, preferred embodiment shown in
The upper pad portion 34 may be positioned near, but below, the valve annulus. In other embodiments of the present invention, the upper pad portion may be positioned directly on the exterior surface of the annulus or somewhat above the annulus to contact the left atrium wall. The position of the upper pad portion preferably avoids direct compressive contact with important vascular structure near or on the exterior surface of the heart. Significant coronary vasculature often lies on or near the atrio-ventricular groove 36, which corresponds with the posterior annular region of the mitral valve. For this reason, it may be desirable to position the upper pad portion onto the left atrial surface.
Anchor assembly 28 permits selection of a position that causes valve annulus shape change relatively independent from the positioning of the ventricular splints that cause ventricular shape change. The incorporation of an anchor assembly 28 is most suitable for instances where the desired shape change for the mitral valve is relatively co-planar with the main ventricular shape change splints. In addition, anchor assembly 28 provides for annulus shape change without the need for an additional MV splint, such as that shown in
An alternative embodiment of a splint with a mitral valve anchor assembly according to the invention is illustrated in
A further alternative anchor assembly 28″ is shown in
In certain cases, the optimal orientation of shape change for improving the mitral valve function may be significantly offset from the position and orientation of transventricular splints 14. It is therefore desirable to have an approach to cause mitral valve shape change at positions away from the transventricular splints 14, and even more desirably, without the addition of another splint structure traversing the ventricle.
Since runner 42 preferably connects to the two anchor pads 18 of the upper-most splint assembly 14, runner 42 generally runs at approximately the same level on the heart wall as those anchor pads 18. In one embodiment, accessory anchor pad structure 40 may be of the same shape and material as the anchor pads 18. While this embodiment may result in significantly improved MVR in some instances, in another embodiment, accessory pad 40 may take a form, including shape and material, similar to the anchor assemblies 28, 28′, 28″ shown in
In one embodiment, runner 52 is a braid formed of a high strength polymer, such as that used in the tension members described in the '049 application incorporated above. A suitable connection mechanism includes the use of one or more pins 56 placed through the braided runner 52 and connected to cap 54 through a flange 58, for example, situated on the cap 54. This pinning connection mechanism may be similar to the connection used for the braided tension members and anchor pads shown and described in the '049 application. The same connection mechanism may be used to connect accessory pad 50 to braided runner 52. In an alternative embodiment according to the present invention, the braided runner 52 may more directly connect to anchor pads 18, without the use of caps 54, by, for example, a pinning securement mechanism incorporated into the superior splint pads themselves. In another contemplated embodiment, the external anchor pad assembly 50, including the runner 52 and anchor pads 18, can be used without the transventricular splint to improve valve function by causing a shape change to the valve annulus without an overall shape change to the left ventricle.
As mentioned above, a mechanism that may exacerbate MVR is the relative rotation of the papillary muscles PM and the adjacent left ventricular wall as the transventricular splints 14 are tightened into position. This relative rotation results in slack in some chordae and tightening in other chordae, which may “pull” one valve leaflet (or portion of the leaflet) while “loosening” the other valve leaflet (or portion of the leaflet).
Connecting bar 60 attaches to the ends of tension members 16 and 72 at their left ventricular “free wall” ends. Both tension members 16 and 72 are tensioned, pressing connecting bar 60 into the left ventricle and effecting shape change to the ventricle and the mitral valve annulus. Connecting bar 60 prevents rotation of the left ventricle LV in the region of the anterior papillary muscle PM and causes uniform tensioning of the chordae associated with that papillary muscle PM and any associated ventricular wall. This is believed to lessen any degradation in MVR, and potentially improve the MVR, because the papillary muscles PM are brought to a more desired position, with less rotation, particularly as to the anterior papillary muscle.
The embodiments of the present invention described in connection with
Moreover, while many of the embodiments of the present invention have been described in connection with modifications to transventricular splinting structures, the same or similar modifications may be made to external-type devices for causing ventricular shape change. Examples of such external devices are shown in co-pending U.S. patent application Ser. No. 09/157,486 (“the '486 application”) filed Sep. 21, 1998 and entitled “External Stress Reduction Device and Method,” now issued as U.S. Pat. No. 6,183,411, the complete disclosure of which is incorporated by reference herein. Modifying those external devices in a similar manner as with the transventricular splints will achieve beneficial impacts to the mitral valve function. For example, the accessory anchor pad shown in
It will be apparent to those skilled in the art that various modifications and variations can be made in the devices and related methods for improving mitral valve function of the present invention and in construction of such devices without departing from the scope or spirit of the invention. As an example, a combination of devices depicted above may be used for achieving improved mitral valve function. In one such combination, an accessory splint such as MV splint 20 shown in
The endovascular techniques which will be described hereinafter do not require performing a sternotomy or removing portions of the heart tissue, nor do they require opening the heart chamber or stopping the heart during operation. Such percutaneous insertion permits the splinting procedures to be performed in a wide variety of laboratories in the hospital. For these reasons, the techniques for implanting the devices of the present invention also are less risky to the patient, both during and after the implantation, and may be performed more quickly than other techniques. For instance, the procedures of the invention cause less pain to patients and permit quicker healing. In addition, certain endovascular splinting techniques to be described may limit bleeding at access sites, allowing relatively large catheters, cannula, and other similar implantation tools to be inserted in a percutaneous manner.
An embodiment of an endovascular splinting technique according to the present invention is shown in
Second, delivery through the right ventricle allows for straightforward positioning of the splints on the ventricular septal wall SW. Such positioning on the septal wall is preferable because it results in good left ventricle bisection, in a manner believed to have minimal negative impact on mitral valve function, and in some instances, a positive impact on mitral valve function and performance. Moreover, delivery through the right ventricle does not involve the free wall of the right ventricle and also does not restrict outflow of the blood from the heart.
According to the right ventricle delivery technique shown in
Additionally, as shown best in
Once catheter 1100 is manipulated to a desired position on the ventricular septum SW, the support wire 1106 is advanced to stabilize the tip position, as shown in
Once needle 1105 is across the left ventricle chamber, its position is confirmed by TEE, X-Ray, or other visualization techniques, to assure good bisection and avoidance of key mitral valve and other heart structure. Conventional angiography utilizing a “pigtail” catheter. i.e., a dye injection catheter with a loop shape at the distal end, in the left ventricle LV and angiography catheters in one or both coronary artery ostia may also be used to aid in proper positioning of the associated delivery devices in the LV. It also is important to assure that needle 1105 will not penetrate or damage any significant coronary vasculature. To assure this, an angiogram may be performed. Preferably, the angiographic image is aligned to a position that looks down the axis of the needle in the portion of the needle which traverses the left ventricle LV. This angle will limit parallax to ensure that if the tip of the needle is not coincident with a significant vessel it will not pierce such vessel. Any small variation in the position of the needle tip can be adjusted by gentle manipulation of the delivery catheter.
As mentioned above, preferably needle 1105 has soft threads 1107 disposed on the surface of a tip portion of the needle, as shown in
Next, delivery catheter 1100 is straightened and advanced over needle 1105 into left ventricle LV. A tapered tip 1101 on delivery catheter 1100 enables catheter 1100 to penetrate the septal and free walls SW, HW. Once distal anchoring balloon 1103 traverses across the free wall HW, both balloons 1102 and 1103 are inflated, as shown in
As delivery catheter 1100 is advanced over the distal end of needle 1105, flexible threads 1107 become collapsed and needle 1105 can be removed from catheter 1100. After removing needle 1105, an elongate tension member 1200 with a heart-engaging assembly, preferably in the form of a collapsible fixed anchor mechanism 1201 (free wall anchor), on its distal end can be inserted into the lumen of catheter 1100. Tension member 1200 is advanced until it begins to emerge from the tip portion 1101 of delivery catheter 1100, as shown in
In this configuration, flexible elastic ring 1203 can be easily deformed into a flattened hoop, without bundles 1210 inhibiting this deformation. This is the configuration that tension member 1200 has as it is advanced through the lumen of delivery catheter 1100. To allow tension member 1200 to be pushed through catheter 1100, a stiffening mandrel may be disposed either inside or adjacent the braided portion of the tension member.
As shown in
After removing delivery catheter 1100, a second heart-engaging assembly, preferably in the form of an adjustable anchor pad 1205 (septal wall anchor) is advanced over tension member 1200 using a deployment tool 1209, as shown in
Adjustable pad 1205 is advanced using deployment tool 1209 over tension member 1200 in essentially a “monorail” fashion, allowing anchor pad 1205 to be oriented substantially adjacent and parallel to tension member 1200 as tension member 1200 slides through throughhole 1205′. Once located at the septal wall SW, a tightening device 1206, preferably in the form of a tube, is advanced over the outside of the tension member until the distal end of the tightening device 1206 engages the adjustable pad 1205. Manipulation of the tightening device 1206 relative to tension member 1200 positions adjustable pad 1205 and tension member 1200 into a position so as to alter the shape of the left ventricle LV.
Once a desired amount of shape change is achieved, adjustable pad 1205 is deployed by manipulation of the deployment tool 1209, in a manner similar to the technique disclosed in the '049 application. That is, the deployment tool 1209 includes an actuator wire that is pre-engaged with an engagement collar (not shown) in adjustable pad assembly 1205 such that when the actuator wire is pulled, the engagement collar travels through various channels disposed within the adjustable anchor pad 1205. The engagement collar causes securement members, preferably in the form of pins or staples, such as staple 1218 shown in
In another embodiment of the invention, splints can be positioned across the left ventricle via an endovascular route leading directly into the left ventricle rather than through the right ventricle. Using this approach, preferably the access site is located in one of the femoral arteries, in a manner similar to many cardiology procedures, for example. Although this route requires advancing delivery tools retrograde across the aortic valve, this delivery route permits the delivery catheter to be placed in approximately the middle of, rather than outside, the left ventricle, thus yielding a more symmetrical approach. The ability to position the splint to achieve a good bisection of the left ventricle therefore may be enhanced since the bisection may be easier to visualize prior to implanting the splints. Furthermore, it may be possible to stabilize the delivery system using walls on both sides of the left ventricle, thus requiring fewer additional support mechanisms.
The direct left ventricle delivery approach uses a guide device, preferably in the form of a delivery catheter, of a different structure than that used in the right ventricle delivery approach. As shown in
Once the distal tip of main catheter 1301 resides in the left ventricle LV, curved catheters 1302, 1303 are advanced with their respective distal anchoring balloons 1304, 1305 inflated. Distal balloons 1304, 1305 serve to act as protective bumpers on the curved catheters so as to avoid damaging various heart structures as the catheters traverse the ventricle. The curvature of catheters 1302, 1303 causes the tips of the catheters to deflect laterally until the distal balloons 1304, 1305 of each catheter 1302, 1303 contact the inside surface of the left ventricle LV, at the septal wall SW and free wall HW, respectively. Once positioned, the curved catheters press against each other to form a self-supporting structure which remains in place during the beating of the heart. Once distal balloons 1304, 1305 contact the walls, sharpened wires 1306, 1307, similar to the one described above in the right ventricle delivery method and shown in detail in
Curved catheters 1302, 1303 then are advanced with both anchor balloons deflated over wires 1306, 1307, similar to the step described above in the right ventricle approach. After catheters 1302, 1303 have been advanced across the ventricular walls SW, HW at the appropriate positions, both balloons on each of curved catheters 1302, 1303 are inflated to keep the catheters securely positioned and stabilized with respect to the chamber walls, as shown in
A tension member 1200, with a first heart-engaging assembly, preferably in the form of a deployable fixed anchor pad mechanism 1201 (free wall anchor), on its distal end, similar to the tension member and deployable fixed pad mechanism discussed with respect to the right ventricle delivery method, is inserted into curved catheter 1303 engaging the free wall HW, as shown in
At this point, tension member 1200 is in a configuration similar to that shown in
In
After tip portion 1400′ of delivery catheter 1300 is positioned and oriented in the desired location with respect to septal wall SW, a hollow sharpened metallic guidewire, or needle, 1402 is advanced through a central lumen 1422 of delivery catheter 1400, across the ventricular septum SW, and across the left ventricular chamber LV to free wall HW, as shown in
Hollow guidewire 1402 has a sharpened tip 1402′ and defines a central lumen plugged near tip 1402′. The material used to make guidewire 1402 preferably includes a superelastic nickel titanium alloy, or other similar like material. Two elastomeric balloons, a distal balloon 1403 and a proximal balloon 1404, are secured near the distal end of guidewire 1402 slightly proximal to sharpened tip 1402′. Distal balloon 1403 is in flow communication with central lumen 1422 of guidewire 1402. Proximal balloon 1404 is in fluid communication with an additional tube (not shown) positioned inside hollow guidewire 1402. In this manner, each balloon 1403, 1404 can be independently inflated and deflated as required.
Balloons 1403, 1404 preferably are in a deflated condition as they are advanced across septal wall SW and then are inflated during advancement across the left ventricle LV. Inflating the balloons during advancement across the left ventricle LV may assist in visualizing the advancement path of the guidewire. To assist in such visualization, preferably the balloons are inflated with a radiographic contrast agent. The ability to visualize the advancement path of guidewire 1402 may prevent damage to various cardiac structure as well as assist in ensuring proper positioning of the guidewire on the free wall HW.
As guidewire tip 1402′ approaches free wall HW, distal balloon 1403 is deflated, as shown in
Proximal balloon 1404 is then deflated, as shown in
Aside from the configurations described above with reference to
Elongate tension member 1500 preferably is similar to that described above in connection with the right ventricle delivery method and comprises a braid of high strength polymer fibers, preferably Spectra or other suitable like ultra-high molecular weight polyethylene. Tension member 1500 may also include a covering along its full length made of a thin expanded polytetrafluoroethylene. Alternatively, only the region of tension member 1500 which is disposed inside the ventricular chamber could include a covering.
Tension member 1500 is thus advanced into position by sliding splint advancement catheter 1406 carrying tension member 1500 and anchor 1502 over guidewire 1402. That is, guidewire 1402 will be placed within lumen 1509 of anchor 1502 and then within lumen 1406′ of the catheter 1406. The lumen 1406′ and the lumen 1509 will move relative to guidewire 1402 to advance catheter 1406, tension member 1500, and anchor 1502 in the configuration shown in
At this point in the splint delivery technique of
In the case where the proximal anchor is slidable on the tension member, a one way “ratchet” or friction surface may be disposed on the inner surface of the tubular portion of the anchor to prevent its displacement in one direction. For example, as shown in
A tightening device such as that described and shown in
In the alternative case where proximal anchor is pre attached at a specified distance from the distal anchor, the left ventricle should be deformed prior to the pad deployment. The delivery catheter can act as a temporary proximal anchor, while the tension member and distal anchor are pulled proximally. Once the proper shape change of the left ventricle is attained, the proximal anchor may be deployed upon further retraction of the sheath of the splint advancement catheter. In this embodiment, preferably the distance between the distal and proximal anchors will be selected prior to delivery such that a desired shape change of the heart chamber may be obtained, since the adjustability of the shape change will be limited by the fixed position of the proximal anchor on the tension member. The delivery catheter may then be removed and excess tension member severed, again as described with reference to
While the splint delivery methods and devices just described in connection with
Other embodiments of a deployable, fixed heart-engaging assembly, or anchor, also are contemplated as within the scope of the present invention and are shown in
For example,
In this embodiment, wire 1345, particularly in the spiral region, preferably will remain together with the braid of tension member 1340 even after diametric expansion in order provide the anchoring rigidity needed to secure the splint in place on the heart. Initially, the spiral portion of wire 1345 may carry a significant portion of the load of anchor 1342. However, it is anticipated that over time, the expanded braid forming anchor 1342 would become ingrown with scar tissue, and therefore a relatively large portion of the chronic mechanical loading may be carried by the filaments of the braid. Using filaments of ultra-high molecular weight polyethylene has been shown to produce a tension member and anchor having high strength and high fatigue resistance. A portion of the wire that does not form the spiral may be removed, for example by torquing the wire and breaking it at a location slightly proximal to the spiral.
To prevent any of the braided portion distal of the expanded region from “creeping” back over the spiral region, the distal most region of the braid preferably is either fused or banded. This will prevent expansibility in those regions. Alternatively, those regions of the braided tension member could be woven with a higher pick count.
An alternative device for causing expansion of an expandable braid portion of a tension member 1540 includes an inflatable balloon disposed inside braided tension member at the expandable portion forming the anchor, as shown in
One of ordinary skill in the art would recognize that the alternative distal anchors described above could be utilized in conjunction with any of the delivery techniques of the present invention and could be used as either the free wall anchor or septal wall anchor with modifications as necessary.
Another alternative embodiment for an expandable anchor would utilize an anchor similar to the expandable tab anchor described above with reference to
An alternative proximal anchor also may utilize the expandable capability of a relatively low pick count braid, in a manner similar to that described above for the distal, or free wall, anchor. In this embodiment, the entire braid of the tension member preferably includes the relatively low pick count permitting diametric expansion. The tension member and distal anchor could be delivered using any of the approaches described herein, but preferably one of the right ventricle approach methods. After the distal, or free wall, anchor is delivered, the proper ventricle shape change can be induced using a tightening device in the form of a simple tube, such as the one described above, but without the anchor shown in
The methods described above to place the splint assemblies with respect to the heart can be repeated for any desired number of splint assemblies to achieve a particular configuration. The length of the tension members extending between the free wall and septal wall anchors also can be optimally determined based upon the size and condition of the patient's heart. It should also be noted that although the left ventricle has been referred to here for illustrative purposes, the apparatus and methods of this invention can be used to splint multiple chambers of a patient's heart, including the right ventricle or either atrium, or can be used to aid the function of valves, such as the mitral valve. An example of a preferred position of a splint assembly 2000 improves mitral valve function, as well as reducing stress in the left ventricular walls. The valve function is improved by aiding in the apposition of valve leaftlets when positioned as shown in
Furthermore, the alignments of the splints with respect to the heart that are described above are illustrative only and may be shifted or rotated about a vertical axis generally disposed through the left ventricle and still avoid the major coronay vessels and papillary muscles. In addition, the inventive devices and methods can be implanted to treat a heart having aneurysms or infarcted regions similar to those described in prior U.S. application Ser. No. 09/422,328 discussed earlier herein and incorported above.
The various components of the splint assembly to be implanted in the heart should be made of biocompatible material that can remain in the human body indefinitely. Any surface engaging portions of the heart should be atraumatic in order to avoid tissue damage and preferably formed of a material promoting tissue ingrowth to stabilize the anchor pad with respect to the surfaces of the heart.
It will be understood that this disclosure, in many respects, is only illustrative. Changes may be made in details, particularly in matters of shape, size, material, number and arrangement of parts without exceeding the scope of the invention. Accordingly, the scope of the invention is as defined in the language of the appended claims.
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
Claims
1-119. (canceled)
120. A method for improving the function of a valve of a heart, the method comprising:
- endovascularly delivering an elongate member and first and second anchoring members to the heart;
- placing the elongate member transverse a heart chamber so that each end of the elongate member extends through a wall of the heart; and
- placing the first and second anchoring members external the chamber, the first and second anchoring members being attached to the ends of the elongate member to fix the elongate member in a position across the chamber, wherein the position is superior to the papillary muscles and proximate and substantially across the valve.
121. The method of claim 120, wherein the heart chamber is the left ventricle and the valve is the mitral valve.
122. The method of claim 121, further comprising advancing the elongate member and first and second anchoring members into the right ventricle and then to the left ventricle.
123. The method of claim 122, further comprising advancing the elongate member from the right ventricle through the septal wall of the heart and to the left ventricle.
124. The method of claim 120, further comprising advancing the elongate member and first and second anchoring members into the heart chamber without entering another heart chamber first.
125. The method of claim 120, wherein the position of the elongate member alters a shape of an annulus of the valve.
126. The method of claim 120, wherein the position of the elongate member repositions the papillary muscles within the chamber.
127. The method of claim 120, wherein endovascularly delivering the elongate member and first and second anchoring members to the heart includes delivering the elongate member and first and second anchoring members into a heart chamber from a vein.
128. The method of claim 120, wherein the elongate member is advanced through a guide device endovascularly inserted into the right ventricle.
129. The method of claim 128, wherein the guide device is a catheter.
130. The method of claim 128, wherein inserting the guide device includes extending the guide device across the left ventricle from the right ventricle through a first location on a free wall surrounding the left ventricle and through a second location on a septal wall.
131. The method of claim 128, wherein inserting the guide device includes stabilizing the guide device with respect to the left ventricle.
132. The method of claim 131, wherein the stabilizing includes inflating balloons disposed proximate a distal end of the guide device.
133. The method of claim 132, wherein the stabilizing includes inflating a first balloon adjacent a first exterior surface of the heart chamber wall and a second balloon adjacent an interior surface of the heart chamber wall.
134. The method of claim 121, wherein the elongate member is advanced through a guide device endovascularly inserted into the left ventricle without first entering another heart chamber.
135. The method of claim 134, wherein the guide device includes a first guide member and a second guide member, said first guide member being configured to extend toward a first interior surface of the chamber wall at a first location and said second guide member being configured to extend toward a second interior surface of the chamber wall at a second location.
136. The method of claim 135, wherein the inserting includes stabilizing said first guide member at the first interior surface and the second guide member at the second interior surface.
137. The method of claim 136, wherein the stabilizing includes inflating balloons disposed proximate the distal end of each of the first and second guide members.
138. The method of claim 137, wherein the stabilizing includes inflating a first balloon on each of the first and second guide members adjacent first and second exterior surfaces of the chamber wall respectively and a second balloon on each of the guide members adjacent the first and second interior surfaces of the chamber wall.
139. The method of claim 135, wherein the first and second guide members are adjustably curvable catheters.
140. The method of claim 120, wherein the first anchoring member is expandable and the method further comprises expanding at least a portion of the first anchoring member.
141. The method of claim 140, wherein the expanding includes applying an outwardly directed force from within the portion of the first anchoring member.
142. The method of claim 141, wherein the applying includes inflating the portion of the first anchoring member.
143. The method of claim 140, wherein the portion of the first anchoring member is made of a shape memory alloy and is self-expandable.
144. The method of claim 120, wherein at least a portion of the first anchoring member is integrally formed with the elongate member.
145. The method of claim 120, wherein the placing the second anchoring member includes adjusting a length of the elongate member between the first and second anchoring members.
146. The method of claim 145, wherein the adjusting the length includes changing the cross-sectional shape of the heart chamber.
147. The method of claim 145, wherein the adjusting the length includes changing the radius of curvature of the heart chamber.
148. The method of claim 145, wherein the adjusting the length includes changing a shape of the valve annulus.
149. The method of claim 120, further comprising inserting a guide device through vasculature structure and into the heart, wherein the delivering includes advancing the elongate member and first and second anchors through the guide device.
150. The method of claim 149, wherein inserting the guide device includes inserting the guide device through a chamber wall at first and second locations.
151. The method of claim 150, wherein the inserting through the chamber wall includes advancing the guide device over a needle extending through the chamber wall at the first and second locations.
152. The method of claim 151, wherein the needle extends from a distal end of the guide device to extend through the chamber wall.
153. A splint for improving the function of a valve of a heart, the splint comprising:
- an elongate member configured to be positioned transverse a heart chamber so that each end of the elongate member extends through a wall of the heart; and
- first and second anchoring members configured to be positioned external the chamber and attached to the ends of the elongate member to fix the elongate member in a position across the chamber,
- wherein the first anchoring member includes a first portion configured to contact a first region of the heart proximate the valve to change a shape of the valve, and
- wherein the elongate member and the first and second anchoring members are configured to be endovascularly delivered to the heart.
154. The splint of claim 153, wherein the heart chamber is the left ventricle and the valve is the mitral valve.
155. The splint of claim 154, wherein the first region of the heart is a superior portion of the left ventricle proximate an annulus of the mitral valve.
156. The splint of claim 154, wherein the first region of the heart is a portion of the left atrium proximate an annulus of the mitral valve.
157. The splint of claim 153, wherein the first portion has an oblong shape.
158. The splint of claim 153, wherein the first anchoring member further includes a second portion configured to contact a second region of the heart below the first region.
159. The splint of claim 158, wherein the second portion includes a first structure connected to the elongate member and a second structure connected to the first portion by the first structure.
160. The splint of claim 153, wherein the elongate member and first and second anchoring members are configured to be delivered via a guide device through vasculature.
161. The splint of claim 154, wherein the elongate member and first and second anchoring members are configured to be delivered into the right ventricle prior to placement of the elongate member transverse the left ventricle.
162. The splint of claim 154, wherein the elongate member and first and second anchoring members are configured to be delivered into the left ventricle without first entering another heart chamber.
163. The splint of claim 153, wherein the second anchoring member is configured to contact a septal wall.
164. A method for improving the function of a valve of a heart, the method comprising:
- endovascularly delivering an elongate member and first and second anchoring members to the heart;
- placing the elongate member transverse a heart chamber so that each end of the elongate member extends through a wall of the heart; and
- placing the first and second anchoring members external the chamber, the first and second anchoring members being attached to first and second ends of the elongate member to fix the elongate member in a position across the chamber so as to reposition papillary muscles within the chamber.
165. The method of claim 164, wherein the first end of the elongate member extends through a wall of the left ventricle between papillary muscles.
166. The method of claim 165, wherein the second end of the elongate member extends through a septum of the heart.
167. The method of claim 164, wherein the chamber is the left ventricle and the valve is the mitral valve.
168. The method of claim 167, further comprising advancing the elongate member and first and second anchoring members into the right ventricle and then to the left ventricle.
169. The method of claim 168, further comprising advancing the elongate member from the right ventricle through the septal wall of the heart and to the left ventricle.
170. The method of claim 164, further comprising advancing the elongate member and first and second anchoring members into the heart chamber without entering another heart chamber first.
171. The method of claim 164, wherein the position is superior to the papillary muscles and proximate and substantially across the valve.
172. The method of claim 164, wherein the elongate member is fixed in the position so as to alter the shape of an annulus of the valve.
173. A method for improving the function of a valve of a heart, comprising:
- placing a multifilament elongate member relative to the heart so that the elongate member contacts cardiac structure other than structure of the valve and alters a shape of the valve;
- adjusting the elongate member relative to the heart; and
- securing the elongate member relative to the heart, wherein the securing includes placing a pin through the elongate member.
174. The method of claim 173, wherein adjusting the elongate member relative to the heart includes adjusting a position of the elongate member relative to an anchor.
175. The method of claim 174, wherein securing the elongate member relative to the heart includes securing the elongate member to the anchor.
176. The method of claim 173, wherein the elongate member is comprised of a polymer.
177. The method of claim 173, wherein placing the elongate member relative to the heart includes placing the elongate member external to the heart chambers.
178. The method of claim 173, wherein the elongate member includes a covering.
179. The method of claim 173, wherein the elongate member is flexible.
180. The method of claim 173, further comprising endovascularly delivering the elongate member to the heart.
181. The method of claim 180, wherein endovascularly delivering the device to the heart includes delivering the device through venous vasculature.
182. The method of claim 180, wherein endovascularly delivering the device to the heart includes delivering the device through arterial vasculature.
183. The method of claim 180, wherein endovascularly delivering the device to the heart includes delivering the device through a catheter having an adjustable tip portion.
184. The method of claim 173, further comprising real-time monitoring valve function.
185. The method of claim 184, wherein the real-time monitoring includes ultrasound imaging the valve.
186. The method of claim 184, wherein adjusting the elongate member relative to the heart is based on data obtained during the adjusting from the real-time monitoring of valve function.
187. The method of claim 173, wherein the multifilament elongate member is braided.
188. The method of claim 120, further comprising real-time monitoring valve function.
189. The method of claim 188, wherein the real-time monitoring includes ultrasound imaging the valve.
Type: Application
Filed: May 7, 2004
Publication Date: Apr 7, 2005
Applicant:
Inventors: Richard Schroeder (Fridley, MN), Robert Vidlund (Maplewood, MN), Jason Kalgreen (Edina, MN), Cyril Schweich (Maple Grove, MN), Todd Mortier (Minneapolis, MN), Marc Simmon (Becker, MN), Peter Keith (St. Paul, MN)
Application Number: 10/840,511
