DELIVERY DEVICES AND METHODS FOR HEART VALVE REPAIR
Devices, systems and methods facilitate positioning of a cardiac valve annulus treatment device, thus enhancing treatment of the annulus. Methods generally involve advancing an anchor delivery device through vasculature of the patient to a location in the heart for treating the valve annulus, contacting the anchor delivery device with a length of the valve annulus, delivering a plurality of coupled anchors from the anchor delivery device to secure the anchors to the annulus, and drawing the anchors together to circumferentially tighten the valve annulus. Devices generally include an elongate catheter having at least one tensioning member and at least one tensioning actuator for deforming a distal portion of the catheter to help it conform to a valve annulus. The catheter device may be used to navigate a subannular space below a mitral valve to facilitate positioning of an anchor delivery device.
The present application is a continuation-in-part of U.S. patent application Ser. No. 10/792,681 (Attorney Docket No. 016886-001330US), filed on Mar. 2, 2004, which is a continuation-in-part of U.S. patent application Ser. No. 10/741,130 (Attorney Docket No. 016886-001320US), filed on Dec. 19, 2003, which is a continuation-in-part of U.S. patent application Ser. Nos. 10/656,797 (Attorney Docket No. 16886-001300US), filed on Sep. 4, 2003, and 10/461,043 (Attorney Docket No. 16886-000310US), filed on Jun. 13, 2003, the latter of which claims the benefit of U.S. Provisional Patent Application Nos. 60/388,935 (Attorney Docket No. 016886-000300US), filed on Jun. 13, 2002; 60/429,288 (Attorney Docket No. 016886-000700US), filed on Nov. 25, 2002; 60/445,890 (Attorney Docket No. 016886-000800US), filed on Feb. 6, 2003; 60/459,735 (Attorney Docket No. 16886-000900US), filed on Apr. 1, 2003; and 60/462,502 (Attorney Docket No. 016886-001100US), filed on Apr. 10, 2003. The full disclosures of all of the above-listed references are hereby incorporated by reference.
The present application is related to U.S. patent application Ser. Nos. 10/______ (Docket No. 16886-001340US); 10/______ (Attorney Docket No. 16886-001350US); 10/______ (Attorney Docket No. 16886-001360US); 10/______ (Attorney Docket No. 16886-001370US); and 10/______ (Attorney Docket No. 16886-001380US), all of which are filed concurrently herewith, and all of which are hereby fully incorporated by reference.
BACKGROUND OF THE INVENTION1. Field of the Invention
The present invention relates generally to medical devices and methods. More particularly, the invention relates to devices, systems and methods for enhancing cardiovascular valve repair, especially the repair of heart valves such as the mitral and tricuspid valves.
In recent years, many advances have been made to reduce the invasiveness of cardiac surgery. In an attempt to avoid open, stopped-heart procedures, which may be accompanied by high patient morbidity and mortality, many devices and methods have been developed for operating on a heart through smaller incisions, operating on a beating heart, and even performing cardiac procedures via transvascular access. Different types of cardiac procedures, such as cardiac ablation techniques for treating atrial fibrillation, stenting procedures for atherosclerosis, and valve repair procedures for treating conditions such as mitral valve regurgitation have experienced significant technological advances. In implementing many minimally invasive cardiac surgery techniques, especially beating-heart techniques, one of the most significant challenges is positioning a treatment device (or multiple devices) in a desired location in or around the heart for performing the procedure. Another challenge, once a device is positioned, is to effectively deploy a given treatment into or on the target cardiac tissue.
One type of cardiac surgery which may benefit from less invasive techniques is heart valve repair. Traditional treatment of heart valve stenosis or regurgitation, such as mitral or tricuspid regurgitation, typically involves an open-heart surgical procedure to replace or repair the valve. Valve repair procedures typically involve annuloplasty, a set of techniques designed to restore the valve annulus shape and strengthen the annulus. Conventional annuloplasty surgery generally requires a large incision into the thorax of the patient (a thoracotomy), and sometimes a median sternotomy (cutting through the middle of the sternum). These open heart, open chest procedures routinely involve placing the patient on a cardiopulmonary bypass machine for sustained periods so that the patient's heart and lungs can be artificially stopped during the procedure. Finally, valve repair and replacement procedures are typically technically challenging and require a relatively large incision through the wall of the heart to access the valve.
Due to the highly invasive nature of open heart valve repair or replacement, many patients, such as elderly patients, patients having recently undergone other surgical procedures, patients with comorbid medical conditions, children, late-stage heart failure patients, and the like, are often considered too high-risk to undergo heart valve surgery and are relegated to progressive deterioration and cardiac enlargement. Often, such patients have no feasible alternative treatments for their heart valve conditions.
To obviate this situation, a number of devices and methods for repairing cardiac valves in a less invasive manner have been described. Some devices provide for heart valve repair through minimally invasive incisions or intravascularly, while others improve upon open heart surgical procedures on beating hearts, stopped hearts or both. As mentioned above, difficulties in performing minimally invasive intracardiac surgery include positioning a minimally invasive treatment device in a desired location for performing a procedure and effectively deploying a given treatment into or on the target cardiac tissue. In heart valve repair procedures, for example, it is often essential for a physician to secure one or more treatment devices to valve annulus tissue. Annular tissue tends to be more fibrous than surrounding muscular or valve leaflet tissue, thus providing a more suitable location for securing such treatment devices, such as anchors, to treat a heart valve. Positioning an anchor deliver device in a desired location adjacent the annular tissue may often be challenging, especially in an intravascular procedure when visualization of the location is limited.
Devices and methods that address these difficulties are described in U.S. patent application Ser. Nos. 10/792,681, 10/741,130, 10/656,797, 10/461,043, 60/388,935, 60/429,288, 60/445,890, 60/462,502 and 60/524,622, which were previously incorporated by reference. For example, these references describe devices and methods for exposing, stabilizing and/or performing a procedure on a heart valve annulus, such as a mitral valve annulus. Many of the devices and methods previously described by the inventors have been found to be highly effective, but improvements are still being sought.
Therefore, it would be beneficial to have improved methods, devices and systems for enhancing heart valve annulus treatment procedures. Ideally, such methods, devices and systems would facilitate positioning of one or more devices in a left ventricle or elsewhere for performing a procedure on a heart valve annulus, visualizing the annulus and/or the like. Additionally, such methods, devices and systems would ideally be introduced intravascularly. At least some of these objectives will be met by the present invention.
2. Description of the Background Art
Published U.S. Application Nos. 2002/0156526, 2003/0220685, 2004/0019378, 2004/0003819, 2004/0030382 and 2004/0039442, and U.S. Pat. Nos. 6,629,534 and 6,619,291 describe catheter-based methods for performing annuloplasty. Published U.S. Application 2002/0042621 describes a heart valve annuloplasty system with constrictable plication bands which are optionally attached to a linkage strip. Published U.S. Application 2002/0087169 describes a remote controlled catheter system which can be used to deliver anchors and a tether for performing an annuloplasty procedure. Other patent publications of interest include WO01/26586; US2001/0005787; US2001/0014800; US2002/0013621; US2002/0029080; US2002/0035361; US2002/0042621; US2002/0095167; and US2003/0074012. U.S. patents of interest include U.S. Pat. No. 4,014,492; U.S. Pat. No. 4,042,979; U.S. Pat. No. 4,043,504; U.S. Pat. No. 4,055,861; U.S. Pat. No. 4,700,250; U.S. Pat. No. 5,366,479; U.S. Pat. No. 5,450,860; U.S. Pat. No. 5,571,215; U.S. Pat. No. 5,674,279; U.S. Pat. No. 5,709,695; U.S. Pat. No. 5,752,518; U.S. Pat. No. 5,848,969; U.S. Pat. No. 5,860,992; U.S. Pat. No. 5,904,651; U.S. Pat. No. 5,961,539; U.S. Pat. No. 5,972,004; U.S. Pat. No. 6,165,183; U.S. Pat. No. 6,197,017; U.S. Pat. No. 6,250,308; U.S. Pat. No. 6,260,552; U.S. Pat. No. 6,283,993; U.S. Pat. No. 6,269,819; U.S. Pat. No. 6,312,447; U.S. Pat. No. 6,332,893; and U.S. Pat. No. 6,524,338. Publications of interest include De Simone et al. (1993) Am. J. Cardiol. 73:721-722, and Downing et al. (2001) Heart Surgery Forum, Abstract 7025. All of the above cited references are hereby incorporated by reference in the present application.
BRIEF SUMMARY OF THE INVENTIONDevices, systems and methods of the present invention are generally used to facilitate transvascular, minimally invasive and other “less invasive” surgical procedures, by facilitating the delivery of treatment devices at a treatment site. “Less invasive,” for the purposes of this application, means any procedure that is less invasive than traditional, large-incision, open surgical procedures. Thus, a less invasive procedure may be an open surgical procedure involving one or more relatively small incisions, a procedure performed via transvascular percutaneous access, a transvascular procedure via cut-down, a laparoscopic or other endoscopic procedure, or the like. Generally, any procedure in which a goal is to minimize or reduce invasiveness to the patient may be considered less invasive. Furthermore, although the terms “less invasive” and “minimally invasive” may sometimes be used interchangeably in this application, neither these nor terms used to describe a particular subset of surgical or other procedures should be interpreted to limit the scope of the invention. Generally, devices and methods of the invention may be used in performing or enhancing any suitable procedure.
The present application typically describes devices, systems and methods for performing heart valve repair procedures, and more specifically heart valve annuloplasty procedures such as mitral valve annuloplasty to treat mitral regurgitation. Devices and methods of the invention, however, may be used in any suitable procedure, both cardiac and non-cardiac. For example, they may be used in procedures to repair any heart valve, to repair an atrial-septal defect, to access and possibly perform a valve repair or other procedure from (or through) the coronary sinus, to place one or more pacemaker leads, to perform a cardiac ablation procedure such as ablating around pulmonary veins to treat atrial fibrillation, and/or the like. In other embodiments, the devices and methods may be used to enhance a laparoscopic or other endoscopic procedure on any part of the body, such as the bladder, stomach, gastroesophageal junction, vasculature, gall bladder, or the like. Therefore, although the following description typically focuses on mitral valve and other heart valve repair, such description should not be interpreted to limit the scope of the invention as defined by the claims.
That being said, the present invention generally provides devices, systems and methods for enhanced treatment of a cardiac valve annulus such as a mitral valve annulus. Methods generally involve contacting an anchor delivery device with a length of a valve annulus, delivering a plurality of coupled anchors from the anchor delivery device to secure the anchors to the annulus, and drawing the anchors together to circumferentially tighten the annulus. One device generally includes an elongate catheter having a housing at or near the distal end for releasably housing a plurality of coupled anchors. The device may be positioned such that the housing abuts or is close to valve annular tissue, such as at an intersection of the left ventricular wall and one or more mitral valve leaflets of the heart. Some embodiments include self-securing anchors, which may change from undeployed to deployed configurations. Anchors may be drawn together to tighten the annulus by cinching a tether slidably coupled with the anchors and/or by a self-deforming member coupled with the anchors. Another device includes a steerable guide catheter for helping position the anchor delivery device for treating a valve annulus.
In many cases, methods of the present invention will be performed on a beating heart. Access to the beating heart may be accomplished by any available technique, including intravascular, transthoracic, and the like. Intravascular access to a heart valve may be achieved using any suitable route or method. To perform a procedure on a mitral valve, for example, in one embodiment a catheter may be advanced through a femoral artery, to the aorta, and into the left ventricle of the heart, to contact a length of the mitral valve. Alternatively, access may be gained through the venous system, to a central vein, into the right atrium of the heart, and across the interatrial septum to the left side of the heart to contact a length of the mitral valve. In either of these two types of intravascular access, the catheter will often easily be advanced, once it enters the left side of the heart, into a space defined by the left ventricular wall, one or more mitral valve leaflets, and chordae tendineae of the left ventricle. This space provides a convenient conduit for further advancement of the catheter to a desired location for performing mitral valve repair. In alternative embodiments, a catheter device may access the coronary sinus and a valve procedure may be performed directly from the sinus. Furthermore, in addition to beating heart access, methods of the present invention may be used for intravascular stopped heart access as well as stopped heart open chest procedures. Any suitable intravascular or other access method is contemplated within the scope of the invention.
In one aspect of the present invention, a device for performing a procedure on heart valve annulus includes: a flexible, elongate catheter having a proximal portion and a shaped distal portion, the distal portion having at least one aperture for allowing passage of tissue anchors; multiple tissue anchors releasably housed in the shaped distal portion; at least one cinchable tether slidably coupled with the tissue anchors; and at least one anchor delivery member housed in the distal portion for delivering the anchors out of the at least one aperture to engage tissue of the valve annulus.
In some embodiments, the shaped distal portion comprises at least a first curve. The first curve may have any suitable shape, radius of curvature or the like, such as in one embodiment where the first curve has a radius of curvature between 0.5 inches and 1.5 inches. In some embodiments, the shaped distal portion further comprises a second curve. The first and second curves may be adapted to orient a distal-most portion of the catheter at an angle of between 45° and 90°, relative to the proximal portion of the catheter immediately adjacent the distal portion. In some embodiments, the second curve has a radius of curvature approximating a radius of curvature of the heart valve. In an alternative embodiment, the second curve has a radius of curvature greater than a radius of curvature of the heart valve, wherein the greater radius of curvature causes the distal portion to press outward against the valve annulus. Optionally, at least one of the first and second curves may have the same shape as a corresponding curve in a guide catheter used for delivering the elongate catheter into contact with the valve annulus. For example, first and second curves in the elongate catheter may correspond to first and second corresponding curves in the guide catheter. In such embodiments, the elongate catheter, when advanced through the guide catheter, is oriented such that the at least one aperture contacts the valve annulus tissue.
Some embodiments of the device further include at least one stabilizing member coupled with the elongate catheter for maintaining the distal portion in contact with valve annulus tissue. In some embodiments, for example, the stabilizing member comprises a spiral-shaped member extending from the distal portion to press against heart wall tissue, thus urging the distal portion against the annulus tissue. Optionally, a distal end of the spiral-shaped member may be adapted to engage and press against a junction of one or more papillary muscles and heart wall tissue. In other embodiments, the stabilizing member comprises an arch-shaped shape-memory or spring-loaded member extending from the distal portion to press against heart wall tissue, thus urging the distal portion against the annulus tissue. In one embodiment, a portion of the arch-shaped member is adapted to engage and press against a junction of one or more papillary muscles and heart wall tissue. The device may optionally further include an expandable member coupled with the arch-shaped member for inflating to further press against the heart wall tissue. In other embodiment, the stabilizing member comprises multiple springs extending from the distal portion to press against heart wall tissue, thus urging the distal portion against the annulus tissue. Alternatively, the stabilizing member may include a curved balloon coupled with the distal portion of the catheter, the curved balloon having a greater radius of curvature than a radius of curvature of the valve annulus. Inflating the balloon thus urges the distal portion against the annulus tissue.
In some embodiments, the device further includes at least one termination member for enhancing attachment of a terminal tissue anchor to the heart valve annulus. In some embodiment, the termination member is slidably couplable with the tether. In some embodiments, the termination member is coupled with the tether via a termination catheter device. The termination member may include, for example, at least one deployable tissue attachment member deployable from a retracted configuration for delivery to an expanded configuration for attachment to the valve annulus tissue. The tissue attachment members may include a plurality of members, such as but not limited to barbs, points, needles, hooks, tines, rakes, wires, teeth and/or the like. In some embodiments, the tissue attachment members comprise a shape-memory or super-elastic material. The tissue attachment members may, for example, be disposed circumferentially about a cylindrical member adapted to slide over the tether. Alternatively, the tissue attachment members may be disposed along a portion of a cylindrical member adapted to slide over the tether.
In some embodiments, the tissue attachment members further include a pusher for pushing the tissue attachment member out of the elongate catheter and into the valve annulus tissue. In some embodiments, the tissue attachment members are adapted to engage the terminal tissue anchor. In one embodiment, the tissue attachment members are adapted to enter into the valve annulus tissue in a direction from the terminal tissue anchor toward the other tissue anchors. Optionally, the tissue attachment members may further include a fiber, matrix, textile or mesh disposed on at least a portion of the tissue attachment member for enhancing tissue in-growth over the tissue attachment member.
In some embodiments, each of the tissue anchors comprises at least one tissue engagement feature for preventing the anchors from being pulled out of the valve annulus tissue when the tether is cinched. For example, the tissue engagement feature(s) may include a barb on each end of each tissue anchor. Such a barb may face inward toward a center of the anchor or outward away from the center. In another embodiment, the tissue engagement features comprise a plurality of bends in each anchor. Optionally, each of the tissue anchors may include at least one support member for preventing the anchors from being pulled out of the valve annulus tissue when the tether is cinched. For example, the support member may comprise an attachment point of one arm of each anchor to another arm of each anchor, the attachment point positioned adjacent an eyelet of the anchor. Optionally, a constraining member may be disposed over the attachment point to provide further support. The constraining member may include, for example, a band, tie, sleeve, belt or the like. In some embodiments of the device, each of the tissue anchors comprises at least one tissue adhesion feature adapted to enhance attachment of the tissue anchors to the valve annulus tissue. For example, the tissue adhesion feature may comprise one or more materials disposed over at least part of each anchor, the material(s) selected to promote encapsulation of the anchors within the valve annulus tissue. In one embodiment, the anchor delivery member comprises an anchor contacting member for contacting and urging the anchors out of the at least one aperture and a pull cord coupled with the anchor contacting member for applying force to the anchor contacting member to contact and urge the anchors.
In another aspect of the invention, a device for constricting a valve annulus in a heart includes a plurality of slidably coupled tissue anchors, each anchor including at least one tissue attachment feature for enhancing attachment of the anchor to valve annulus tissue, and at least one cinchable tether slidably coupled with at least some of the tissue anchors and fixedly attached to at least a first of the anchors. The tissue attachment features may comprise any of a number of suitable features. In one embodiment, for example, a surface feature is included along at least a portion of each anchor, such as a porous, textured or coated surface. In other embodiments, the attachment feature comprises at least one circular or hooked portion of each anchor having a small radius of curvature. Alternatively or additionally, the attachment feature may comprise a barb at each end of each anchor.
In another aspect of the invention, a method of constricting a valve annulus in a heart involves: contacting a shaped distal portion of an anchor delivery catheter device with a length of the valve annulus; delivering a plurality of slidably coupled anchors from the anchor delivery device to secure the anchors to the annulus; drawing the anchors together to circumferentially tighten the valve annulus; and promoting attachment of the anchors to valve annulus tissue to help secure the anchors to the tissue over time. In some embodiments, contacting the distal portion comprises advancing the catheter device through a shaped introducer device, a shape of the shaped distal portion corresponding to a shape of the introducer device. In such embodiments, advancing the catheter device through the introducer devices may orient one or more apertures on the catheter device with the valve annulus tissue, so that the anchors are delivered into the tissue.
In some embodiments, the method includes stabilizing the distal portion of the catheter device against the valve annulus tissue. For example, stabilizing may involve deploying at least one stabilizing member from the distal portion of the catheter device to contact heart wall tissue of the heart. Optionally, the method may further include securing at least one termination member to the valve annulus tissue, to help maintain attachment of the coupled anchors to the tissue. In one embodiment, for example, securing the termination member involves sliding the termination member along a tether slidably coupled with the anchors and deploying tissue engagement means on the termination member from an unexpanded to an expanded configuration to engage the valve tissue. Some embodiments further include engaging the tissue engagement means with at least a terminal anchor of the plurality of anchors.
Promoting attachment of the anchors to the tissue may be achieved via any of a number of different methods in various embodiments. For example, in one embodiment promoting anchor attachment comprises contacting at least one surface feature of each anchor with the tissue. The surface features may include one or more of those described above, such as a porous surface, a roughened surface, a coated surface and/or an abrasive surface.
In another aspect of the present invention, a method for contacting a shaped distal portion of an anchor delivery catheter with a mitral valve annulus of a heart involves advancing the anchor delivery catheter through a shaped guide catheter into the left ventricle to contact the mitral valve. In this method, at least one bend in the shaped distal portion of the delivery device has approximately the same radius of curvature at least one corresponding bend in the guide catheter, so that advancing the distal portion of the delivery catheter through the at least one corresponding bend positions one or more anchor delivery apertures of the anchor delivery catheter in contact with the mitral valve annulus.
These and other aspects and embodiments are described more fully below with reference to the drawing figures.
Devices, systems and methods of the present invention are generally used to facilitate transvascular, minimally invasive and other “less invasive” surgical procedures, by facilitating the delivery of treatment devices at a treatment site. Although the following description focuses on use of devices and methods of the invention for mitral valve repair, the devices and methods may be used in any suitable procedure, both cardiac and non-cardiac. When used for treatment of a cardiac valve annulus, the inventive methods generally involve contacting an anchor delivery device with a length of the valve annulus, delivering a plurality of coupled anchors from the anchor delivery device, and drawing the anchors together to tighten the annulus. Devices include an elongate catheter having a housing at or near the distal end for releasably housing a plurality of coupled anchors, as well as delivery devices for facilitating advancement and/or positioning of an anchor delivery device. Devices may be positioned such that the housing abuts or is close to valve annular tissue, such as in a location within the left ventricle defined by the left ventricular wall, a mitral valve leaflet and chordae tendineae. Self-securing anchors having any of a number of different configurations may be used in some embodiments. Additional devices include delivery devices for facilitating delivery and/or placement of an anchor delivery device at a treatment site.
In many cases, methods of the present invention will be performed on a beating heart. Access to the beating heart may be accomplished by any available technique, including intravascular, transthoracic, and the like. In addition to beating heart access, the methods of the present invention may be used for intravascular stopped heart access as well as stopped heart open chest procedures.
Referring now to
In other embodiments, access to the heart H may be transthoracic, with delivery device 100 being introduced into the heart via an incision or port on the heart wall. Even open heart surgical procedures may benefit from methods and devices of the invention. Furthermore, some embodiments may be used to enhance procedures on the tricuspid valve annulus, adjacent the tricuspid valve leaflets TVL, or any other cardiac or vascular valve. Therefore, although the following description typically focuses on minimally invasive or less invasive mitral valve repair for treating mitral regurgitation, the invention is in no way limited to that use.
With reference now to
Distal portion 102 may be advanced into position under the valve annulus by any suitable technique, some of which are described below in further detail. Generally, distal portion 102 may be used to deliver anchors to the valve annulus, to stabilize and/or expose the annulus, or both. In one embodiment, using a delivery device having a flexible elongate body as shown in
In some embodiments, distal portion 102 includes a shape-changing portion which enables distal portion 102 to conform to the shape of the valve annulus VA. The catheter may be introduced through the vasculature with the shape-changing distal portion in a generally straight, flexible configuration. Once it is in place beneath the leaflet at the intersection between the leaflet and the interior ventricular wall, the shape of distal portion 102 is changed to conform to the annulus and usually the shape is “locked” to provide sufficient stiffness or rigidity to permit the application of force from distal portion 102 to the annulus. Shaping and optionally locking distal portion 102 may be accomplished in any of a number of ways. For example, in some embodiments, a shape-changing portion may be sectioned, notched, slotted or segmented and one of more tensioning members such as tensioning cords, wires or other tensioning devices coupled with the shape-changing portion may be used to shape and rigidify distal portion 102. A segmented distal portion, for example, may include multiple segments coupled with two tensioning members, each providing a different direction of articulation to the distal portion. A first bend may be created by tensioning a first member to give the distal portion a C-shape or similar shape to conform to the valve annulus, while a second bend may be created by tensioning a second member to articulate the C-shaped member upwards against the annulus. In another embodiment, a shaped expandable member, such as a balloon, may be coupled with distal portion 102 to provide for shape changing/deforming. In various embodiments, any configurations and combinations may be used to give distal portion 102 a desired shape.
In transthoracic and other embodiments, distal portion 102 may be shaped, and the method may simply involve introducing distal portion 102 under the valve leaflets. The shaped distal portion 102 may be rigid or formed from any suitable super-elastic or shape memory material, such as nitinol, spring stainless steel, or the like.
In addition to delivering anchors to the valve annulus VA, delivery device 100 (and specifically distal portion 102) may be used to stabilize and/or expose the valve annulus VA. Such stabilization and exposure are described fully in U.S. patent application Ser. No. 10/656,797, which was previously incorporated by reference. For example, once distal portion 102 is positioned under the annulus, force may be applied to distal portion 102 to stabilize the valve annulus VA, as shown in
Some embodiments may include a stabilization component as well as an anchor delivery component. For example, some embodiments may include two flexible members, one for contacting the atrial side of a valve annulus and the other for contacting the ventricular side. In some embodiments, such flexible members may be used to “clamp” the annulus between them. One of such members may be an anchor delivery member and the other may be a stabilization member, for example. Any combination and configuration of stabilization and/or anchor delivery members is contemplated.
Referring now to
Although delivery device 108 is shown having a circular cross-sectional shape in
With reference now to
Housing 206 may be flexible or rigid in various embodiments. In some embodiments, for example, flexible housing 206 may be comprised of multiple segments configured such that housing 206 is deformable by tensioning a tensioning member coupled to the segments. In some embodiments, housing 206 is formed from an elastic material having a geometry selected to engage and optionally shape or constrict the valve annulus. For example, the rings may be formed from super-elastic material, shape memory alloy such as Nitinol, spring stainless steel, or the like. In other instances, housing 206 could be formed from an inflatable or other structure can be selectively rigidified in situ, such as a gooseneck or lockable element shaft, any of the rigidifying structures described above, or any other rigidifying structure.
“Anchors,” for the purposes of this application, is defined to mean any fasteners. Thus, anchors 210 may comprise C-shaped or semicircular hooks, curved hooks of other shapes, straight hooks, barbed hooks, clips of any kind, T-tags, or any other suitable fastener(s). In one embodiment, as described above, anchors may comprise two tips that curve in opposite directions upon deployment, forming two intersecting semi-circles, circles, ovals, helices or the like. In some embodiments, anchors 210 are self-deforming. By “self-deforming” it is meant that anchors 210 change from a first undeployed shape to a second deployed shape upon release of anchors 210 from restraint in housing 206. Such self-deforming anchors 210 may change shape as they are released from housing 206 and enter valve annulus tissue, to secure themselves to the tissue. Thus, a crimping device or other similar mechanism is not required on distal end 202 to apply force to anchors 210 to attach them to annular tissue.
Self-deforming anchors 210 may be made of any suitable material, such as a super-elastic or shape-memory material like Nitinol or spring stainless steel. In other embodiments, anchors 210 may be made of a non-shape-memory material and made be loaded into housing 206 in such a way that they change shape upon release. Alternatively, anchors 210 that are not self-deforming may be used, and such anchors may be secured to tissue via crimping, firing or the like. Even self-securing anchors may be crimped in some embodiments, to provide enhanced attachment to tissue. In some embodiments, anchors 210 may comprise one or more bioactive agent. In another embodiment, anchors 210 may comprise electrodes. Such electrodes, for example, may sense various parameters, such as but not limited to impedance, temperature and electrical signals. In other embodiments, such electrodes may be used to supply energy to tissue at ablation or sub-ablation amounts. Delivery of anchors may be accomplished by any suitable device and technique, such as by simply releasing the anchors by hydraulic balloon delivery as discussed further below. Any number, size and shape of anchors 210 may be included in housing 206.
In one embodiment, anchors 210 are generally C-shaped or semicircular in their undeployed form, with the ends of the C being sharpened to penetrate tissue. Midway along the C-shaped anchor 210, an eyelet may be formed for allowing slidable passage of tether 212. To maintain anchors 210 in their C-shaped, undeployed state, anchors 210 may be retained within housing 206 by two mandrels 214, one mandrel 214 retaining each of the two arms of the C-shape of each anchor 210. Mandrels 214 may be retractable within elongate catheter body 204 to release anchors 210 and allow them to change from their undeployed C-shape to a deployed shape. The deployed shape, for example, may approximate a complete circle or a circle with overlapping ends, the latter appearing similar to a key ring. Such anchors are described further below, but generally may be advantageous in their ability to secure themselves to annular tissue by changing from their undeployed to their deployed shape. In some embodiments, anchors 210 are also configured to lie flush with a tissue surface after being deployed. By “flush” it is meant that no significant amount of an anchor protrudes from the surface, although some small portion may protrude.
Tether 212 may be one long piece of material or two or more pieces and may comprise any suitable material, such as suture, suture-like material, a Dacron strip or the like. Retaining mandrels 214 may also have any suitable configuration and be made of any suitable material, such as stainless steel, titanium, Nitinol, or the like. Various embodiments may have one mandrel, two mandrels, or more than two mandrels.
In some embodiments, anchors 210 may be released from mandrels 214 to contact and secure themselves to annular tissue without any further force applied by delivery device 200. Some embodiments, however, may also include one or more expandable members 208, which may be expanded to help drive anchors 210 into tissue. Expandable member(s) 208 may have any suitable size and configuration and may be made of any suitable material(s). Hydraulic systems such as expandable members are known in the art, and any known or as yet undiscovered expandable member may be included in housing 206 as part of the present invention.
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In
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In the embodiment shown in
Retracting contacting member 530 to push anchors 526 out of apertures 528 may help cause anchors 526 to avidly secure themselves to adjacent tissue. Using anchors 526 that are relatively straight/flat when undeployed allows anchors 526 with relatively large deployed sizes to be disposed in (and delivered from) a relatively small housing 522. In one embodiment, for example, anchors 526 that deploy into a shape approximating two intersecting semi-circles, circles, ovals, helices, or the like, and that have a radius of one of the semi-circles of about 3 mm may be disposed within a housing 522 having a diameter of about 5 French (1.67 mm) and more preferably 4 French (1.35 mm) or even smaller. Such anchors 526 may measure about 6 mm or more in their widest dimension. In some embodiments, housing 522 may have a diametrical dimension (“d”) and anchor 526 may have a diametrical dimension (“D”) in the deployed state, and the ratio of D to d may be at least about 3.5. In other embodiments, the ratio of D to d may be at least about 4.4, and more preferably at least about 7, and even more preferably at least about 8.8. These are only examples, however, and other larger or smaller anchors 526 may be disposed within a larger or smaller housing 522. Furthermore, any convenient number of anchors 526 may be disposed within housing 522. In one embodiment, for example, housing 522 may hold about 1-20 anchors 526, and more preferably about 3-10 anchors 526. Other embodiments may hold more anchors 526.
Anchor contacting member 530 and pull cord 532 may have any suitable configuration and may be manufactured from any material or combination of materials. In alternative embodiments, contacting member 530 may be pushed by a pusher member to contact and deploy anchors 526. Alternatively, any of the anchor deployment devices and methods previously described may be used.
Tether 534, as shown in
Expandable member 524 is an optional feature of anchor delivery device 520, and thus may be included in some embodiments and not in others. In other words, a distal portion of anchor delivery device 520 may include housing, contents of housing, and other features either with or without an attached expandable member. Expandable member 524 may comprise any suitable expandable member currently known or discovered in the future, and any method and substance(s) may be used to expand expandable member 524. Typically, expandable member 524 will be coupled with a surface of housing 522, will have a larger radius than housing 522, and will be configured such that when it is expanded as housing 522 nears or contacts the valve annulus, expandable member 524 will push or press housing 522 into enhanced contact with the annulus. For example, expandable member 524 may be configured to expand within a space near the corner formed by a left ventricular wall and a mitral valve leaflet.
With reference now to
Generally, delivery device 520 may be advanced into any suitable location for treating any valve by any suitable advancing or device placement method. Many catheter-based, minimally invasive devices and methods for performing intravascular procedures, for example, are well known, and any such devices and methods, as well as any other devices or method later developed, may be used to advance or position delivery device 520 in a desired location. For example, in one embodiment a steerable guide catheter is first advanced in retrograde fashion through an aorta, typically via access from a femoral artery. The steerable catheter is passed into the left ventricle of the heart and thus into the space formed by the mitral valve leaflets, the left ventricular wall and cordae tendineae of the left ventricle. Once in this space, the steerable catheter is easily advanced along a portion (or all) of the circumference of the mitral valve. A sheath is advanced over the steerable catheter within the space below the valve leaflets, and the steerable catheter is removed through the sheath. Anchor delivery device 520 may then be advanced through the sheath to a desired position within the space, and the sheath may be removed. In some cases, an expandable member coupled to delivery device 520 may be expanded to wedge or otherwise move delivery device 520 into the corner formed by the left ventricular wall and the valve leaflets to enhance its contact with the valve annulus. Of course, this is but one exemplary method for advancing delivery device 520 to a position for treating a valve, and any other suitable method, combination of devices, etc. may be used.
As shown in
Referring now to
In one embodiment, cinching tether 534, attaching tether 534 to most-proximal anchor 526, and cutting tether 534 are achieved using a termination device (not shown). The termination device may comprise, for example, a catheter advancable over tether 534 that includes a cutting member and a nitinol knot or other attachment member for attaching tether 534 to most-proximal anchor. The termination catheter may be advanced over tether 534 to a location at or near the proximal end of the tethered anchors 526. It may then be used to apply opposing force to the most-proximal anchor 526 while tether 534 is cinched. Attachment and cutting members may then be used to attach tether 534 to most-proximal anchor 526 and cut tether 534 just proximal to most-proximal anchor 526. Such a termination device is only one possible way of accomplishing the cinching, attachment and cutting steps, and any other suitable device(s) or technique(s) may be used.
In some embodiments, it may be advantageous to deploy a first number of anchors 526 along a first portion of a valve annulus VA, cinch the first anchors to tighten that portion of the annulus, move the delivery device 520 to another portion of the annulus, and deploy and cinch a second number of anchors 526 along a second portion of the annulus. Such a method may be more convenient, in some cases, than extending delivery device 520 around all or most of the circumference of the annulus, and may allow a shorter, more maneuverable housing 522 to be used.
In an embodiment similar to that shown in
In another embodiment, a distal portion of delivery device 520 may be detachable from a proximal portion of delivery device 520. Such an embodiment may be configured such that when anchors 526 are deployed from device 520, the distal portion of device 520 detaches from the proximal portion and is attached, via anchors 526, to the valve annulus VA. In one embodiment, for example, anchors 526 may pierce through the distal portion of device 520, rather than exiting device 520 through apertures 528. The distal portion may be detachable via any suitable means, such as perforations or the like.
Referring now to
With reference now to
With reference now to
In a number of cases, and with reference now to
In an alternative embodiment, pictured in
As shown in
Referring now to
A number of different variations of locking members are contemplated in various embodiments. For example, a two-pronged member may be used, with the prongs deployable from a delivery position to and expanded configuration, and with the prongs optionally engaging with the terminal anchor 710. In another embodiment, multiple prongs may be aligned in a linear fashion along a locking member, such as in a rake-like configuration. Yet another embodiment include two prongs for engaging with the terminal anchor 710 and another prong for engaging with valve annulus tissue VA. Thus, any of a number of different embodiments may be employed as part of the present invention. Such locking members may be constructed from any suitable material or combination of materials, such as Nitinol, spring stainless steel and/or other shape memory or super-elastic materials.
Next, as in
In various embodiments, alternative means may be used to urge anchor delivery device 558 into contact with the valve annulus. For example, in one embodiment an expandable member is coupled with anchor delivery device 558 and expanded within the subannular space 552. In an alternative embodiment, a magnet may be coupled with anchor delivery device 558, and another anchor may be disposed within the coronary sinus, in proximity to the first magnet. The two magnets may attract one another, thus pulling the anchor delivery device 558 into greater contact with the annulus. In another embodiment, anchor delivery device 558 in an expanded (or deployed) state may have a radius of curvature that is larger than the radius of curvature of the mitral valve annulus, thus causing device 558 to be urged against the annulus. In one embodiment, for example, the radius of curvature of device 558 in the expanded/deployed state is about 25%-50% larger than the radius of curvature of the mitral valve annulus.
Various embodiments may also include visualizing the annulus using a visualization member coupled with the anchor delivery device 558 or separate from the device 558. In some embodiments, anchors may be driven through a strip of detachable, biocompatible material, such as Dacron, that is coupled with anchor delivery device 558 but that detaches to affix to the valve annulus via the anchors. In some embodiments, the strip may then be cinched to tighten the annulus. In other embodiments, the anchors may be driven through a detachable, biocompatible, distal portion of the guide sheath 556, and guide sheath 556 may then remain attached to the annulus via the anchors. Again, in some embodiments, the detached sheath may be cinched to tighten the annulus.
Of course, the method just described is but one embodiment of a method for delivering an anchor delivery device to a location for treating a valve annulus. In various alternative embodiments, one or more steps may be added, deleted or modified while achieving a similar result. In some embodiments, a similar method may be used to treat the mitral valve from a superior/right atrial position or to treat another heart valve. Additionally, other devices or modifications of the system just described may be used in other embodiments.
With reference now to
Generally, proximal portion 562 of the catheter body is less flexible than distal portion 564. Proximal portion 562 may be made of any suitable material, such as PEBAX, FEP, nylon, polyethylene and/or the like, and may include a braided material, such as stainless steel, to provide stiffness and strength. Distal portion 564 may be made of similar or other materials, but the braided material is typically not included, to provide for greater flexibility. Both proximal and distal portions 562/564 may have any suitable lengths, diameters, overall configurations and the like. In one embodiment the catheter body is approximately 140 cm in length and 6 French in diameter, but any other suitable sizes may be used in other embodiments. Either proximal portion 562, distal portion 564 or preferably both, may be made from or coated with one or more friction resistant or lubricating material to enhance passage of device 560 through an introducer catheter and/or to enhance passage of a sheath or other device over catheter device 560.
With reference now to
In the embodiments just described or in alternative embodiments, tissue anchors may also have one or more features designed to enhance ingrowth and/or encapsulation of the anchors into annular tissue. Such features, for example, may include a coating, a porous and/or rough surface, an attachment such as a polyester band or belt, or any other suitable surface feature or added feature. By promoting encapsulation of tissue anchors, attachment strength of the anchors to tissue is enhanced.
Referring now to
In an alternative embodiment, as shown in
Referring now to
With reference now to
Although the foregoing is a complete and accurate description of the present invention, the description provided above is for exemplary purposes only, and variations may be made to the embodiments described without departing from the scope of the invention. Thus, the above description should not be construed to limit the scope of the invention as described in the appended claims.
Claims
1-42. (canceled)
43. A device for constricting a valve annulus in a heart, the device comprising:
- a plurality of slidably coupled tissue anchors, each anchor including at least one tissue attachment feature for enhancing attachment of the anchor to valve annulus tissue; and
- at least one cinchable tether slidably coupled with at least some of the tissue anchors and fixedly attached to at least a first of the anchors.
44. A device as in claim 43, wherein the at least one attachment feature comprises a porous surface along at least a portion of each anchor.
45. A device as in claim 43, wherein the at least one attachment feature comprises a textured surface along at least a portion of each anchor.
46. A device as in claim 43, wherein the at least one attachment feature comprises a coated surface along at least a portion of each anchor.
47. A device as in claim 43, wherein the at least one attachment feature comprises at least one circular or hooked portion of each anchor having a small radius of
- curvature.
48. A device as in claim 43, wherein the at least one attachment feature comprises a barb at each end of each anchor.
49-59. (canceled)
Type: Application
Filed: Oct 16, 2009
Publication Date: Apr 1, 2010
Inventors: Niel F. Starksen (Los Altos, CA), John To (Newark, CA), Mariel Fabro (San Jose, CA), Michael F. Wei (Redwood City, CA), Rodolfo A. Morales (Los Gatos, CA)
Application Number: 12/581,040
International Classification: A61F 2/24 (20060101);
