US20050107811A1 - Delivery devices and methods for heart valve repair - Google Patents

Abstract

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.

Description

CROSS REFERENCE TO RELATED APPLICATIONS
• 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. No. 10/656,797 (Attorney Docket No. 16886-001300US), filed on Sep. 4, 2003, and Ser. No. 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 herby incorporated by reference.
• The present application further claims the benefit of U.S. Provisional Patent Application No. 60/524,622 (Attorney Docket No. 16886-001310US), filed Nov. 24, 2003, the full disclosure of which is hereby incorporated by reference. The present application is related to U.S. patent Application Nos. 10/______(Attorney Docket No. 16886-001340US); 10/______(Attorney Docket No. 16886-001350US); 10/______(Attorney Docket No. 16886-001370US); 10/______(Attorney Docket No. 16886-001380US); and 10/______(Attorney Docket No. 16886-001390US), all of which are filed concurrently herewith, and all of which are hereby fully incorporated by reference.
BACKGROUND OF THE INVENTION
• 1. 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. Nos. 4,014,492; 4,042,979; 4,043,504; 4,055,861; 4,700,250; 5,366,479; 5,450,860; 5,571,215; 5,674,279; 5,709,695; 5,752,518; 5,848,969;5,860,992; 5,904,651; 5,961,539; 5,972,004; 6,165,183; 6,197,017; 6,250,308; 6,260,552; 6,283,993; 6,269,819; 6,312,447; 6,332,893; and 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, Abstract7025. All of the above cited references are hereby incorporated by reference in the present application.
BRIEF SUMMARY OF THE INVENTION
• 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. “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, an anchor assembly for use within a patient includes: a catheter-type housing, having an open interior, constructed to be passable through a blood vessel and into a heart; a series of tissue-engageable anchors removably housed within the housing, the anchors comprising a distal anchor and a proximal anchor within the open interior of the housing; and a tether serially coupling the anchors to one another. In one embodiment, at least a portion of the housing is flexible. Such an embodiment may optionally further include means for urging the flexible portion of the housing from a first configuration to a second, radially outwardly expanded, curved configuration. In some embodiments, the housing is steerable.
• In some embodiments, the distal anchor is fixed to the tether and the proximal anchor is slidably coupled to the tether. Also in some embodiments, the tether may be located substantially external of the catheter-type housing. In one embodiment, the anchors are self-forming and self-securing. In one embodiment, at least one of the anchors comprises a bioactive agent. Alternatively, at least one of the anchors may comprise an electrode. For example, such an electrode may sense at least one of impedance, temperature, and electrical signals. In another embodiment, the electrode comprises an energy-application electrode to supply energy to tissue at least one of ablation and sub-ablation amounts.
• In another aspect of the present invention, an anchor assembly for use within a patient includes: a catheter-type housing, having an open interior, constructed to be passable through a blood vessel and into a heart, at least a portion of the housing being flexible; means for urging the flexible portion of the housing from a first configuration to a second, radially outwardly expanded, curved configuration; a series of tissue-engageable anchors removably housed within the open interior of the the housing, the anchors comprising a distal anchor fixed to the tether and a proximal anchor slidably coupled to the tether; the anchors being self-forming and self-securing anchors; and a tether serially coupling the anchors to one another.
• In another aspect of the invention, an anchor device for use within a patient includes: an elongate housing having a longitudinal axis; a self-forming tissue-engageable anchor carried by and deployable from of the housing; the anchor having a first part and a second part, the second part having a tissue-piercing tip; the anchor placeable in a relatively straight, undeployed state generally parallel to the longitudinal axis when carried by the housing; and the anchor naturally assuming a curved, tissue-engaging deployed state after being deployed from the housing. In one embodiment, the elongate housing has an open interior; the anchor is carried within and deployable from the open interior; and the housing has an opening sized for passage of the anchor therethrough when the anchor is deployed from the housing.
• Optionally, at least a portion of the elongate housing may be flexible. In some embodiments, the elongate housing is steerable. In one embodiment, the anchor comprises the first part and at least two of the second parts extending from the first part. In one embodiment, for example, the second parts extend in directions generally opposite one another when in the deployed state. In one such embodiment, the second parts of said anchor have generally circular or semicircular shapes when in the deployed state.
• In some embodiments, the anchor is oriented generally perpendicular to the longitudinal axis when in the deployed state. Also in some embodiments, the second part of the anchor may have a generally circular or semicircular shape when in the deployed state. In some embodiments, the device may further comprise a series of the anchors, the anchors comprising a distal anchor and a proximal anchor, and a tether serially coupling the anchors to one another. In some embodiments, the housing has the diametrical dimension d and the anchor in the deployed state has a diametrical dimension D, and the ratio of D to d is at least about 3.5. In other embodiments, the ratio of D to d is at least about 4.4, and more preferably at least about 7, and even more preferably at least about 8.8. As mentioned above, in some embodiments, the anchor may comprise a bioactive agent or electrode.
• In another aspect of the present invention, a tissue anchor assembly comprises: an anchor comprises: a base and a resilient, self-forming, tissue-engaging portion extending from the base, the tissue-engaging portion comprising a tissue-piercing tip; the tissue-engaging portion movable between a curved, unrestrained state and a restrained state; a coupling element coupled to the anchor; a housing; and the anchor releasably mounted to the housing with the tissue-engaging portion in the restrained state, the tissue-engaging portion transferable from the restrained state to the unrestrained state when the anchor is released from the housing so that the tissue-piercing tip passing into tissue secures the anchor to the tissue as the tissue-engaging portion moves to the curved, unrestrained state without any further force applied to the anchor.
• In some embodiments, the tissue-engaging portion has a generally circular or semicircular shape when in the unrestrained state. In some embodiments, the tissue-engaging portion is straightened when in the restrained state. Optionally, the anchor may comprise first and second of the tissue-engaging portions. For example, in one embodiment, the first tissue-engaging portion comprises a hook. In another embodiment, each of the first and second tissue-engaging portions comprises a hook. In such an embodiment, for example, the hooks may extend in directions generally opposite one another when in the unrestrained state. Other tissue-engaging portions may also extend in directions generally opposite one another when in the unrestrained state.
• In some embodiments, the coupling element comprises a tether coupled to the base of the anchor. In one embodiment, the tether is slidably coupled to the base of the anchor. In another embodiment, the coupling element comprises a flexible string-like element. In such embodiments, the housing may comprise a tubular housing. Optionally, the anchor may be releasably mounted within the tubular housing. Optionally, the device may further include a plurality of anchors with the coupling element coupled to each anchor. In some embodiments, at least one anchor is slidably coupled to the coupling element and another of the anchors is fastened to the coupling element.
• In another aspect of the present invention, a tissue anchor assembly comprises: a plurality of anchors, each anchor comprising a base and first and second self-forming, tissue-engaging portions extending from the base, the tissue-engaging portions each comprising a tissue-piercing tip; the tissue-engaging portions each movable between a curved, unrestrained state and a straightened, restrained state; the tissue-engaging portions each having a generally circular or semicircular shape when in the unrestrained state; a tether coupled to the bases of the anchors; at least one said anchor being slidably coupled to the tether and another of said anchors being fastened to the tether; a housing; and the anchors and tether being releasably mounted to the housing with the tissue-engaging portions in the restrained state, the tissue-engaging portions transferable from the restrained state to the unrestrained state when the anchors and tether are released from the housing so that the tissue-piercing tips passing into tissue secures the anchor to the tissue as the tissue-engaging portion moves to the curved, unrestrained state without any further force applied to the anchor.
• In another aspect of the invention, a tissue anchor assembly includes: an anchor comprising a base and a resilient, self-forming, tissue-engaging portion extending from the base, the tissue-engaging portion comprising a tissue-piercing tip; the tissue-engaging portion movable between a curved, unrestrained state and a restrained state; a coupling element coupled to the anchor; a housing; the anchor releasably mounted to the housing with the tissue-engaging portion in the restrained state, the tissue-engaging portion transformable from the restrained state to the unrestrained state when the anchor is released from the housing; and the tissue-engaging portion comprising means for pulling the anchor into the tissue as the tissue-piercing tip passes into tissue and the tissue-engaging portion moves to the curved, unrestrained state. In various embodiments, the assembly may include any of the features described above.
• In some embodiments, the assembly may further include a plurality of anchors with the coupling element coupled to each anchor. In some embodiments, at least one anchor is slidably coupled to the coupling element and another of said anchors is fastened to the coupling element. In some embodiments, the anchor pulling means comprises means for storing potential energy when in the restrained state. Again, in various embodiments the anchor(s) may comprise a bioactive agent or an electrode. For example, the electrode may sense at least one of impedance, temperature, and electrical signals. Alternatively, the electrode may comprise an energy-application electrode to supply energy to tissue at least one of ablation and sub-ablation amounts.
• In another aspect of the present invention, a tissue anchor assembly includes: a plurality of anchors, each anchor comprising a base and a first and second resilient, self-forming, tissue-engaging portions extending from the base, the tissue-engaging portions each comprising a tissue-piercing tip; the tissue-engaging portions each movable between a curved, unrestrained state and a restrained state; the tissue-engaging portions each having a generally circular or semicircular shape when in the unrestrained state; a coupling element coupled to each of the anchors; a tubular housing; the anchors releasably mounted within the housing with the tissue-engaging portions in the restrained state, the tissue-engaging portions transformable from the restrained state to the unrestrained state when the anchors are released from the housing; the tissue-engaging portions comprising means for pulling the anchors into the tissue as the tissue-piercing tips pass into tissue and the tissue-engaging portions move to the curved, unrestrained states; and the anchor pulling means comprising means for storing potential energy when in the restrained state.
• In another aspect of the invention, a method for securing an anchor to tissue of a patient comprises directing an anchor assembly, comprising an anchor carried by an anchor carrier, to a target tissue site, and releasing the anchor from the anchor carrier. The releasing step comprises: placing a tissue-piercing tip of the anchor into engagement with the tissue at the target tissue site; and the anchor pulling itself into the tissue as the anchor moves from a restrained state to an unrestrained state. In some embodiments, the anchor assembly directing step is carried out with a tubular anchor carrier releasably housing the anchor. In some embodiments, the anchor assembly directing step is carried out with the anchor having a first part and a second part, the second part naturally assuming a curved shape when the anchor is in the unrestrained state. Alternatively, the second part may naturally assume a generally circular or semicircular shape when the anchor is in the unrestrained state. In another embodiment, the anchor assembly directing step is carried out with the anchor having a first part and at least two second parts, each second part naturally assuming a curved, generally circular or semicircular shape when the anchor is in the unrestrained state. In such embodiments, the anchor pulling step may comprise bracing the two second parts against one another through the first part whereby problems associated with tissue deflection are at least substantially reduced.
• In some embodiments, the anchor assembly directing step is carried out with a plurality of the anchors coupled to one another by a tether, each anchor having a first part and a second part, the second part naturally assuming a curved, generally circular or semicircular shape when the anchor is in the unrestrained state. In other embodiments, the anchor assembly directing step is carried out with a plurality of the anchors coupled to one another by a tether, each anchor having a first part and at least two second parts, each second part naturally assuming a curved, generally circular or semicircular shape when the anchor is in the unrestrained state. Optionally, the directing step may be carried out with an anchor comprising a bioactive agent. In other embodiments, the directing step is carried out with an anchor comprising an electrode. Such a method may further comprise sensing, through the electrode, at least one of impedance, temperature, and electrical signals. Alternatively, such a method may further involve supplying the electrode energy in at least one of ablation and sub-ablation amounts.
• These and other aspects and embodiments are described more fully below with reference to the drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a cross-sectional view of a heart with a flexible anchor delivery device being positioned for treatment of a mitral valve annulus, according to one embodiment of the present invention;
• FIGS. 2A and 2B are cross-sectional views of a portion of a heart, schematically showing positioning of a flexible device for treatment of a mitral valve annulus, according to one embodiment of the present invention;
• FIGS. 2C and 2D are cross-sectional views of a portion of a heart, showing positioning of a flexible anchor delivery device for treatment of a mitral valve annulus, according to one embodiment of the present invention;
• FIG. 3 is a perspective view of a distal portion of an anchor delivery device, according to one embodiment of the invention;
• FIG. 4. is a perspective view of a segment of a distal portion of an anchor delivery device, with anchors in an undeployed shape and position;
• FIG. 5 is a different perspective view of the segment of the device shown inFIG. 4;
• FIG. 6. is a perspective view of a segment of a distal portion of an anchor delivery device, with anchors in a deployed shape and position;
• FIGS. 7A-7E are cross-sectional views of an anchor delivery device, illustrating a method for delivering anchors to valve annulus tissue, according to one embodiment of the invention;
• FIGS. 8A and 8B are top-views of a plurality of anchors coupled to a self-deforming coupling member or “backbone,” with the backbone shown in an undeployed shape and a deployed shape;
• FIGS. 9A-9C are various perspective views of a distal portion of a flexible anchor delivery device according to one embodiment of the present invention;
• FIGS. 10A-10F demonstrate a method for applying anchors to a valve annulus and cinching the anchors to tighten the annulus, using an anchor delivery device according to an embodiment of the invention;
• FIG. 11 shows a heart in cross-section with a guide catheter device advanced through the aorta into the left ventricle according to an embodiment of the invention;
• FIG. 11A shows a distal end of an anchor delivery device passing through a guide catheter according to an embodiment of the invention;
• FIG. 11B shows middle portions of an anchor delivery device and a guide catheter having corresponding orientation portions according to an embodiment of the invention;
• FIGS. 12A-12D show various embodiments of support members for supporting an anchor delivery device against a valve annulus;
• FIGS. 13A-13C show a device and method for facilitating termination and load distribution of a series of anchors according to one embodiment of the invention;
• FIGS. 14A-14F demonstrate a method for advancing an anchor delivery device to a position for treating a heart valve according to an embodiment of the invention;
• FIGS. 15A and 15B are side cross-sectional views of a guide catheter device for facilitating positioning of an anchor delivery device according to an embodiment of the invention;
• FIGS. 16A-16E show improved tissue anchors according to various embodiments of the present invention;
• FIGS. 17A-17C show a self-forming anchor attaching to tissue of a valve annulus according to one embodiment of the present invention;
• FIG. 18 shows a self-forming anchor attaching to tissue of a valve annulus according to another embodiment of the present invention;
• FIG. 19A shows an anchor device having a sleeve between two adjacent anchors according to one embodiment of the invention; and
• FIG. 19B shows an anchor device having a sleeve between three anchors according to one embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
• 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 toFIG. 1, a heart H is shown in cross section, with an elongateanchor delivery device100 introduced within the heart H. Generally,delivery device100 comprises an elongate body with adistal portion102 configured to deliver anchors to a heart valve annulus. (InFIGS. 1, 2A and2B,distal portion102 is shown diagrammatically without anchors or anchor-delivery mechanism to enhance clarity of the figures.) In some embodiments, the elongate body comprises a rigid shaft, while in other embodiments it comprises a flexible catheter, so thatdistal portion102 may be positioned in the heart H and under one or more valve leaflets to engage a valve annulus via a transvascular approach. Transvascular access may be gained, for example, through the internal jugular vein (not shown) to the superior vena cava SVC to the right atrium RA, across the interatrial septum to the left atrium LA, and then under one or more mitral valve leaflets MVL to a position within the left ventricle (LV) under the valve annulus (not shown). Alternatively, access to the heart may be achieved via the femoral vein and the inferior vena cava. In other embodiments, access may be gained via the coronary sinus (not shown) and through the atrial wall into the left atrium. In still other embodiments, access may be achieved via a femoral artery and the aorta, into the left ventricle, and under the mitral valve. This access route will be described in further detail below. Any other suitable access route is also contemplated within the scope of the present invention.
• In other embodiments, access to the heart H may be transthoracic, withdelivery device100 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 toFIGS. 2A and 2B, a method for positioningdelivery device100 for treating a mitral valve annulus VA is depicted diagrammatically in a cross-sectional view. First, as inFIG. 2A,distal portion102 is positioned in a desired location under a mitral valve leaflet L and adjacent a ventricular wall VW. (Again,distal portion102 is shown without anchors or anchor-delivery mechanism for demonstrative purposes.) The valve annulus VA generally comprises an area of heart wall tissue at the junction of the ventricular wall VW and the atrial wall AW that is relatively fibrous and, thus, significantly stronger that leaflet tissue and other heart wall tissue.
• Distal portion102 may be advanced into position under the valve annulus by any suitable technique, some of which are described below in further detail. Generally,distal portion102 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 inFIG. 1, a flexibledistal portion102 may be passed from the right atrium RA through the interatrial septum in the area of the foramen ovale (not shown—behind the aorta A), into the left atrium LA and thus the left ventricle LV. Alternatively, flexibledistal portion102 may be advanced through the aorta A and into the left ventricle LV, for example using access through a femoral artery. Oftentimes,distal portion102 will then naturally travel, upon further advancement, under the posterior valve leaflet L into a space defined above asubvalvular space104 roughly defined for the purposes of this application as a space bordered by the inner surface of the left ventricular wall VW, the inferior surface of mitral valve leaflets L, and cordae tendineae CT connected to the ventricular wall VW and the leaflet L. It has been found that a flexible anchor delivery catheter, such as the delivery devices of the present invention, when passed under the mitral valve via an intravascular approach, often enterssubvalvular space104 relatively easily and may be advanced alongspace104 either partially or completely around the circumference of the valve. Once inspace104,distal portion102 may be conveniently positioned at the intersection of the valve leaflet(s) and the ventricular wall VW, which intersection is immediately adjacent or very near to the valve annulus VA, as shown inFIG. 2A. These are but examples of possible access routes of an anchor delivery device to a valve annulus, and any other access routes may be used.
• In some embodiments,distal portion102 includes a shape-changing portion which enablesdistal portion102 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 ofdistal portion102 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 fromdistal portion102 to the annulus. Shaping and optionally lockingdistal portion102 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 rigidifydistal portion102. 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 withdistal portion102 to provide for shape changing/deforming. In various embodiments, any configurations and combinations may be used to give distal portion102 a desired shape.
• In transthoracic and other embodiments,distal portion102 may be shaped, and the method may simply involve introducingdistal portion102 under the valve leaflets. The shapeddistal portion102 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 device100 (and specifically distal portion102) 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, oncedistal portion102 is positioned under the annulus, force may be applied todistal portion102 to stabilize the valve annulus VA, as shown inFIG. 2B. Such force may be directed in any suitable direction to expose, position and/or stabilize the annulus. For example, upward and lateral force is shown inFIG. 2B by the solid-headed arrow drawn from the center ofdistal portion102. In other cases, only upward, only lateral, or any other suitable force(s) may be applied. With application of force todistal portion102, the valve annulus VA is caused to rise or project outwardly, thus exposing the annulus for easier viewing and access. The applied force may also stabilize the valve annulus VA, also facilitating surgical procedures and visualization.
• 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 toFIGS. 2C and 2D, ananchor delivery device108 is shown delivering ananchor110 to a valve annulus VA. Of course, these are again representational figures and are not drawn to scale.Anchor110 is shown first housed within delivery device108 (FIG. 2C) and then delivered to the annulus VA (FIG. 2D). As is shown, in one embodiment anchors110 may have a relatively straight configuration when housed indelivery device108, perhaps with two sharpened tips and a loop in between the tips. Upon deployment fromdelivery device108, the tips ofanchor110 may curve in opposite directions to form two semi-circles, circles, ovals, overlapping helices or the like. This is but one example of a type of self-securing anchor which may be delivered to a valve annulus. Typically, multiple coupledanchors110 are delivered, and theanchors110 are drawn together to tighten the valve annulus. Methods for anchor delivery and for drawing anchors together are described further below.
• Althoughdelivery device108 is shown having a circular cross-sectional shape inFIGS. 2C and 2D, it may alternatively have any other suitable shape. In one embodiment, for example, it may be advantageous to provide a delivery device having an ovoid or elliptical cross-sectional shape. Such a shape may help ensure that the device is aligned, when positioned between in a corner formed by a ventricular wall and a valve leaflet, such that one or more openings in the delivery device is oriented to deliver the anchors into valve annulus tissue. To further enhance contacting of the valve annulus and/or orientation of the delivery device, some embodiments may further include an expandable member, coupled with the delivery device, which expands to urge or press or wedge the delivery device into the corner formed by the ventricle wall and the leaflet to contact the valve annulus. Such enhancements are described further below.
• With reference now toFIG. 3, one embodiment of a portion of ananchor delivery device200 suitably includes anelongate shaft204 having adistal portion202 configured to deliver a plurality ofanchors210, coupled with atether212, to tissue of a valve annulus.Tethered anchors210 are housed within ahousing206 ofdistal portion202, along with one or moreanchor retaining mandrels214 and anexpandable member208. Many variations may be made to one or more of these features, and various parts may be added or eliminated, without departing from the scope of the invention. Some of these variations are described further below, but no specific embodiment(s) should be construed to limit the scope of the invention as defined by the appended claims.
• Housing206 may be flexible or rigid in various embodiments. In some embodiments, for example,flexible housing206 may be comprised of multiple segments configured such thathousing206 is deformable by tensioning a tensioning member coupled to the segments. In some embodiments,housing206 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,housing206 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, anchors210 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, anchors210 are self-deforming. By “self-deforming” it is meant that anchors210 change from a first undeployed shape to a second deployed shape upon release ofanchors210 from restraint inhousing206. Such self-deforminganchors210 may change shape as they are released fromhousing206 and enter valve annulus tissue, to secure themselves to the tissue. Thus, a crimping device or other similar mechanism is not required ondistal end202 to apply force toanchors210 to attach them to annular tissue.
• Self-deforminganchors210 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, anchors210 may be made of a non-shape-memory material and made be loaded intohousing206 in such a way that they change shape upon release. Alternatively, anchors210 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, anchors210 may comprise one or more bioactive agent. In another embodiment, anchors210 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 ofanchors210 may be included inhousing206.
• In one embodiment, anchors210 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-shapedanchor210, an eyelet may be formed for allowing slidable passage oftether212. To maintainanchors210 in their C-shaped, undeployed state, anchors210 may be retained withinhousing206 by twomandrels214, onemandrel214 retaining each of the two arms of the C-shape of eachanchor210.Mandrels214 may be retractable withinelongate catheter body204 to releaseanchors210 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, anchors210 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.
• Tether212 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. Retainingmandrels214 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, anchors210 may be released frommandrels214 to contact and secure themselves to annular tissue without any further force applied bydelivery device200. Some embodiments, however, may also include one or moreexpandable members208, which may be expanded to help driveanchors210 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 inhousing206 as part of the present invention.
• Referring now toFIGS. 4 and 5, a segment of adistal portion302 of an anchor delivery device suitably includes ahousing306, multiple tensioningmembers320 for applying tension tohousing306 to change its shape, twoanchor retaining mandrels314 slidably disposed inhousing306,multiple anchors310 slidably coupled with atether312, and anexpandable member308 disposed betweenanchors310 andhousing306. As can be seen inFIGS. 4 and 5,housing306 may include multiple segments to allow the overall shape ofhousing306 to be changed by applying tension to tensioningmembers320. As also is evident from the drawings, “C-shaped” anchors310 may actually have an almost straight configuration when retained bymandrels314 inhousing306. Thus, for the purposes of this application, “C-shaped” or “semicircular” refers to a very broad range of shapes including a portion of a circle, a slightly curved line, a slightly curved line with an eyelet at one point along the line, and the like.
• With reference now toFIG. 6, the same segment ofdistal portion302 is shown, butmandrels314 have been withdrawn from twomandrel apertures322, to releaseanchors310 fromhousing306. Additionally,expandable member308 has been expanded to drive anchors out ofhousing306.Anchors310, having been released frommandrels314, have begun to change from their undeployed, retained shape to their deployed, released shape.
• Referring now toFIGS. 7A-7E, a cross-section of adistal portion402 of an anchor delivery device is shown in various stages of delivering an anchor to tissue of a valve annulus VA. InFIG. 7A,distal portion402 is positioned against the valve annulus, ananchor410 is retained by twomandrels414, atether412 is slidably disposed through an eyelet onanchor410, and anexpandable member408 is coupled withhousing406 in a position to driveanchor410 out ofhousing406. When retained bymandrels414,anchor410 is in its undeployed shape. As discussed above,mandrels414 may be slidably retracted, as designated by the solid-tipped arrows inFIG. 7A, to releaseanchor410. In various embodiments, anchors410 may be released one at a time, such as by retractingmandrels414 slowly, may be released in groups, or may all be released simultaneously, such as by rapid retraction ofmandrels414.
• InFIG. 7B,anchor410 has begun to change from its undeployed shape to its deployed shape (as demonstrated by the hollow-tipped arrows) and has also begun to penetrate the annular tissue VA.Empty mandrel apertures422 demonstrate thatmandrels414 have been retracted at least far enough to releaseanchor410. InFIG. 7B,expandable member408 has been expanded to driveanchor410 partially out ofhousing406 and further into the valve annulus VA.Anchor410 also continues to move from its undeployed towards its deployed shape, as shown by the hollow-tipped arrows. InFIG. 7D,anchor410 has reached its deployed shape, which is roughly a completed circle with overlapping ends or a “key ring” shape. InFIG. 7E,delivery device402 has been removed, leaving a tethered anchor in place in the valve annulus. Of course, there will typically be a plurality of tethered anchors secured to the annular tissue. Tether412 may then be cinched to apply force toanchors410 and cinch and tighten the valve annulus.
• With reference now toFIGS. 8A and 8B, a diagrammatic representation of another embodiment of coupled anchors is shown. Here, anchors510 are coupled to a self-deforming or deformable coupling member orbackbone505.Backbone505 may be fabricated, for example, from Nitinol, spring stainless steel, or the like, and may have any suitable size or configuration. In one embodiment, as inFIG. 8A,backbone505 is shaped as a generally straight line when held in an undeployed state, such as when restrained within a housing of an anchor deliver device. When released from the delivery device,backbone505 may change to a deployed shape having multiple bends, as shown inFIG. 8B. By bending,backbone505 shortens the longitudinal distance between anchors, as demonstrated by the solid-tipped arrows inFIG. 8B. This shortening process may act to cinch a valve annulus into which anchors510 have be secured. Thus, anchors510 coupled tobackbone505 may be used to cinch a valve annulus without using a tether or applying tethering force. Alternatively, a tether may also be coupled withanchors510 to further cinch the annulus. In such an embodiment,backbone505 will be at least partially conformable or cinchable, such that when force is applied toanchors510 andbackbone505 via a tether,backbone505 bends further to allow further cinching of the annulus.
• Referring now toFIGS. 9A-9C, in one embodiment a flexible distal portion of ananchor delivery device520 suitably includes ahousing522 coupled with anexpandable member524.Housing522 may be configured to house multiple coupledanchors526 and ananchor contacting member530 coupled with apull cord532.Housing522 may also includemultiple apertures528 for allowing egress ofanchors526. For clarity,delivery device520 is shown without a tether inFIGS. 9A and 9C, butFIG. 9B shows that atether534 may extend through an eyelet, loop or other portion of eachanchor526, and may exit eachaperture528 to allow for release of the plurality ofanchors526. The various features of this embodiment are described further below.
• In the embodiment shown inFIGS. 9A-9C, anchors526 are relatively straight and lie relatively in parallel with the long axis ofdelivery device522.Anchor contacting member530, which may comprise any suitable device, such as a ball, plate, hook, knot, plunger, piston, or the like, generally has an outer diameter that is nearly equal to or slightly less than the inner diameter ofhousing522. Contactingmember530 is disposed within the housing, distal to adistal-most anchor526, and is retracted relative tohousing522 by pullingpull cord532. When retracted,anchor contacting member530 contacts and applies force to adistal-most anchor526 to release cause that anchor526 to exithousing522 via one of theapertures528. Contactingmember530 is then pulled farther proximally to contact and apply force to thenext anchor526 to deploy thatanchor526, and so on.
• Retracting contactingmember530 to pushanchors526 out ofapertures528 may help causeanchors526 to avidly secure themselves to adjacent tissue. Usinganchors526 that are relatively straight/flat when undeployed allowsanchors526 with relatively large deployed sizes to be disposed in (and delivered from) a relativelysmall housing522. In one embodiment, for example, anchors526 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 ahousing522 having a diameter of about 5 French (1.67 mm) and more preferably 4 French (1.35 mm) or even smaller.Such anchors526 may measure about 6 mm or more in their widest dimension. In some embodiments,housing522 may have a diametrical dimension (“d”) andanchor526 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 orsmaller anchors526 may be disposed within a larger orsmaller housing522. Furthermore, any convenient number ofanchors526 may be disposed withinhousing522. In one embodiment, for example,housing522 may hold about 1-20anchors526, and more preferably about 3-10anchors526. Other embodiments may holdmore anchors526.
• Anchor contacting member530 andpull cord532 may have any suitable configuration and may be manufactured from any material or combination of materials. In alternative embodiments, contactingmember530 may be pushed by a pusher member to contact and deployanchors526. Alternatively, any of the anchor deployment devices and methods previously described may be used.
• Tether534, as shown inFIG. 9B, may comprise any of thetethers534 or tether-like devices already described above, or any other suitable device. Tether534 is generally attached to adistal-most anchor526 at anattachment point536. The attachment itself may be achieved via a knot, weld, adhesive, or by any other suitable attachment means. Tether234 then extends through an eyelet, loop or other similar configuration on each on each of theanchors526 so as to be slidably coupled with theanchors526. In the embodiment shown,tether534 exits eachaperture528, then enters the next-most-proximal aperture, passes slidably through a loop on ananchor526, and exits thesame aperture528. By entering and exiting eachaperture528,tether534 allows the plurality ofanchors526 to be deployed into tissue and cinched. Other configurations ofhousing522, anchors526 andtether534 may alternatively be used. For example,housing522 may include a longitudinal slit through whichtether534 may pass, thus allowingtether534 to reside wholly within housing before deployment.
• Expandable member524 is an optional feature ofanchor delivery device520, and thus may be included in some embodiments and not in others. In other words, a distal portion ofanchor delivery device520 may include housing, contents of housing, and other features either with or without an attached expandable member.Expandable member524 may comprise any suitable expandable member currently known or discovered in the future, and any method and substance(s) may be used to expandexpandable member524. Typically,expandable member524 will be coupled with a surface ofhousing522, will have a larger radius thanhousing522, and will be configured such that when it is expanded ashousing522 nears or contacts the valve annulus,expandable member524 will push or presshousing522 into enhanced contact with the annulus. For example,expandable member524 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 toFIGS. 1A-10F, a method is shown for applying a plurality oftethered anchors526 to a valve annulus VA in a heart. As shown inFIG. 10A, ananchor delivery device520 is first contacted with the valve annulus VA such thatopenings528 are oriented to deployanchors526 into the annulus. Such orientation may be achieved by any suitable technique. In one embodiment, for example, ahousing522 having an elliptical cross-sectional shape may be used to orientopenings528. As just described, contact betweenhousing522 and the valve annulus VA may be enhanced by expandingexpandable member524 to wedge housing within a corner adjacent the annulus.
• Generally,delivery device520 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 orposition delivery device520 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 device520 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 todelivery device520 may be expanded to wedge or otherwise movedelivery device520 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 advancingdelivery device520 to a position for treating a valve, and any other suitable method, combination of devices, etc. may be used.
• As shown inFIG. 10B, whendelivery device520 is positioned in a desired location for deployinganchors526,anchor contacting member530 is retracted to contact and apply force to a most-distal anchor526 to begin deployinganchor526 throughaperture528 and into tissue of the valve annulus VA.FIG.10C show anchor526 further deployed out ofaperture528 and into valve annulus VA.FIG. 10D shows the valve annulus VA transparently so that further deployment ofanchors526 can be seen. As shown, in one embodiment of the invention, anchors526 include two sharpened tips that move in opposite directions upon release fromhousing522 and upon contacting the valve annulus VA. Between the two sharpened tips, ananchor526 may be looped or have any other suitable eyelet or other device for allowing slidable coupling with atether534.
• Referring now toFIG. 10E, anchors526 are seen in their fully deployed or nearly fully deployed shape, with each pointed tip (or “arm”) of eachanchor526 having curved to form a circle or semi-circle. Of course, in various embodiments anchors526 may have any other suitable deployed and undeployed shapes, as described more fully above.FIG. 10F showsanchors526 deployed into the valve annulus VA and coupled withtether534, with thedistal-most anchor526 coupled attached fixedly to tether524 atattachment point536. At this stage,tether534 may be cinched to tighten the annulus, thus reducing valve regurgitation. In some embodiments, valve function may be monitored by means such as echocardiogram and/or fluoroscopy, andtether534 may be cinched, loosened, and adjusted to achieve a desired amount of tightening as evident via the employed visualization technique(s). When a desired amount of tightening is achieved,tether534 is then attached to a most-proximal anchor526 (or two or more most-proximal anchors526), using any suitable technique, andtether534 is then cut proximal to the most-proximal anchor526, thus leaving the cinched,tethered anchors526 in place along the valve annulus VA. Attachment oftether534 to the most-proximal anchor(s)526 may be achieved via adhesive, knotting, crimping, tying or any other technique, and cuttingtether534 may also be performed via any technique, such as with a cutting member coupled withhousing522.
• In one embodiment, cinchingtether534, attachingtether534 to most-proximal anchor526, and cuttingtether534 are achieved using a termination device (not shown). The termination device may comprise, for example, a catheter advancable overtether534 that includes a cutting member and a nitinol knot or other attachment member for attachingtether534 to most-proximal anchor. The termination catheter may be advanced overtether534 to a location at or near the proximal end of the tethered anchors526. It may then be used to apply opposing force to the most-proximal anchor526 whiletether534 is cinched. Attachment and cutting members may then be used to attachtether534 to most-proximal anchor526 and cuttether534 just proximal to most-proximal anchor526. 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 ofanchors526 along a first portion of a valve annulus VA, cinch the first anchors to tighten that portion of the annulus, move thedelivery device520 to another portion of the annulus, and deploy and cinch a second number ofanchors526 along a second portion of the annulus. Such a method may be more convenient, in some cases, than extendingdelivery device520 around all or most of the circumference of the annulus, and may allow a shorter, moremaneuverable housing522 to be used.
• In an embodiment similar to that shown inFIGS. 10A-10F, an analogous method may be used but anchors526 may be driven out ofdelivery device520 through a biocompatible material attached todelivery device520, thereby attaching the biocompatible material to the valve annulus VA. For example, in one embodiment a Dacron strip may be attached todelivery device520, extending alongdevice520 and coveringapertures528.Anchors526 are then driven out ofdelivery device520, through the Dacron strip, into the valve annulus VA, thus detaching the Dacron strip fromdevice520 and attaching it to the valve annulus VA. Such a biocompatible material may facilitate tissue ingrowth ofanchors526 and may enhance attachment generally to the valve annulus VA. In an alternative embodiment, multiple pieces of biocompatible material, such as separate pieces of material disposed over each ofapertures528, may be used. For example, in one embodiment multiple discs of Dacron material are disposed overmultiple apertures528.
• In another embodiment, a distal portion ofdelivery device520 may be detachable from a proximal portion ofdelivery device520. Such an embodiment may be configured such that when anchors526 are deployed fromdevice520, the distal portion ofdevice520 detaches from the proximal portion and is attached, viaanchors526, to the valve annulus VA. In one embodiment, for example, anchors526 may pierce through the distal portion ofdevice520, rather than exitingdevice520 throughapertures528. The distal portion may be detachable via any suitable means, such as perforations or the like.
• Referring now toFIG. 11, a cross-sectional depiction of a heart H is shown with an anchor deliverydevice guide catheter550 advanced through the aorta A and into the left ventricle LV. In a preferred embodiment, this access route to the subannular space and the valve annulus may used.Guide catheter550 is generally a flexible elongate catheter which may have one or more curves or bends toward its distal end to facilitate placement of the distal end ofcatheter550 in asubannular space552.Subannular space552, which has been described above in detail, is generally defined by the left ventricular wall, the mitral valve leaflets MVL, and cordae tendiniae, and travels along most or all of the circumference of the valve annulus. The distal end ofguide catheter550 may be configured to be positioned at an opening intospace552 or withinspace552, such that subsequent catheter devices may be passed throughguide catheter550 intospace552. In some embodiments, it may be advantageous to provideguide catheter550 with a curvable portion with a radius in an expanded/curved state that is greater than a radius of the valve annulus. For example, in oneembodiment guide catheter550 in the expanded state has a radius about 25%-50% larger that the valve annulus.
• With reference now toFIG. 11A, a distal portion ofguide catheter550 is shown, with ananchor delivery device558 extending through it and out of its distal end. As shown, in oneembodiment guide catheter550 includes at least onebend551 or curvature, andanchor delivery device558 is pre-shaped to include at least onecorresponding bend553, that has approximately the same radius of curvature as thebend551 inguide catheter550. In some embodiments (not shown),guide catheter550 may havemultiple bends551, andanchor delivery device558 may have multiple corresponding bends553. In the embodiment shown,anchor delivery device558 includes aproximal bend553, which corresponds to thebend551 inguide catheter550, and adistal bend555. By matching the radii of curvature of theproximal bend553 and theguide catheter bend551, the distal portion ofanchor delivery device558 becomes automatically oriented (when advanced through guide catheter550) such that one or moreanchor delivery apertures557 are in contact with the valve annulus (not shown). Moreover,distal bend555 may have a radius of curvature that matches approximately a radius of curvature of a valve annulus. Alternatively,distal bend555 may have a radius of curvature greater than a valve annulus radius of curvature, such that the distal portion ofanchor delivery device558 tends to push radially outward, enhancing contact of thedevice558 with valve annulus tissue. Such greater radii of curvature are described in greater detail below.Proximal bend553 anddistal bend555 may therefore have any suitable angles relative to one another and relative to the more proximal portion ofanchor delivery device558. In some embodiments,anchor delivery device558 is also steerable.
• With reference now toFIG. 1B, in the embodiment described immediately above and/or in alternative embodiments, ananchor delivery device588 and aguide catheter590 may include one or more corresponding (or “registering”) bends ororientation portions592a,592bat other locations along their lengths. In other words, althoughbends551,553,555 are shown inFIG. 11A at or near the distal ends ofguide catheter550 andanchor delivery device558, similar bends could be formed at more proximal locations. For example,FIG. 11B showsguide catheter590 withorientation portion592ahaving a chosen shape when relaxed. The chosen shape may lie along a two-dimensional or three-dimensional path.Anchor delivery device588 has acorresponding orientation portion592balong its length which is complementary to the shape oforientation portion592a. The chosen shape may also be created by the application of energy, mechanical manipulation or the like.Such orientation portions592a,592bcould be used for further registering or orientingdelivery device588 to a desired orientation. Typically, whenorientation portions592a,592bare axially aligned, which can be indicated by orientation markers at the proximal ends ofguide catheter590 andanchor delivery device588 external of the patient, proper rotary orientation can be sensed tactically by the physician to help insure the distal end ofanchor delivery device588 is properly oriented.Delivery device588 may be rotated, advanced or moved in any suitable fashion withinguide catheter590 to achieve a desired orientation. The use of one or morecomplementary orientation portions592a,592bmay be used with any of a number of various embodiments of guide catheters and anchor delivery devices.
• In a number of cases, and with reference now toFIGS. 12A-12D, it may be advantageous to provide further support to ananchor delivery device658, to support thedevice658 against valve annulus tissue and/or to push thedevice658 against valve annulus tissue to enhance contact with, and anchor delivery into, the tissue. In one embodiment, as shown inFIG. 12A, ahelical support member652 may be coupled with a distal end ofanchor delivery device658 and may be extended into the left ventricle of a heart (or other heart chamber in other embodiments) to contact theheart wall651 and thus supportanchor delivery device658 against the valve annulus tissue. In alternative embodiments,helical support member651 may extend out of aguide catheter650 to contact theheart wall651 and supportanchor delivery device658. Any suitable means may be used for extendinghelical member652 into the left ventricle or other chamber. For example,helical member652 is pushed out ofguide catheter650 in one embodiment, but may alternatively be extended out ofanchor delivery device658.Helical member652 may be made of any suitable material, such as but not limited to Nitinol, stainless steel or the like.
• In an alternative embodiment, pictured inFIG. 12B, a deployableU-shaped support member662 may be movably coupled with a distal portion of ananchor delivery device668, both of which are advanceable through aguide catheter660. Upon being advanced out of the distal end ofguide catheter660,U-shaped member662 may automatically spring out, or alternatively may be manually manipulated to extend outward, to contact the inner surface of the heart wall and/or to contact apapillary muscle663. As shown inFIG. 12B, in one embodimentU-shaped member663 contacts an intersection of apapillary muscle663 with the heart wall, and thus provides upward support (solid-tipped arrows) to anchordelivery device668. Again, such aU-shaped member662 may automatically deform from a straight configuration for delivery throughguide catheter660 into a U-shaped configuration, such as ifmember662 is made of Nitinol, spring stainless steel, or other shape memory or super-elastic material. Alternatively,U-shaped member662 may be connected to anchordelivery device668 at or near the distal end of thedevice668 and may be pushed distally to force theU-shaped member662 to expand into its U-shape. In an alternative embodiment,U-shaped member662 may be attached proximally and may be pulled into its expanded configuration. Any suitable method for changing the shape ofU-shaped member662 from straight to U-shaped may be used in various embodiments.
• As shown inFIG. 12C,U-shaped member662 may optionally include anexpandable member667, such as an inflatable balloon.Expandable member667 may be expanded to provide further force against and support ofanchor delivery device668, to enhance its contact with valve annulus tissue. In another embodiment, as shown inFIG. 12D,multiple spring members672 may be coupled with a distal end of ananchor delivery device678 to provide force against an inner surface of a heart wall (solid tipped arrows) to thus supportanchor delivery device678 against annulus tissue (hollow tipped arrows). Thus, various embodiments of the invention may include any of a number of suitable support devices for enhancing support of an anchor delivery device against valve annulus tissue, thus enhancing the ability of the delivery device to delivery tissue anchors into the annulus.
• Referring now toFIGS. 13A-13C, in some embodiments it may be advantageous to provide one or more devices to enhance the attachment of aterminal tissue anchor710 to valve annulus tissue VA. Typically, in attaching tissue anchors to valve annulus tissue VA, a first tethered anchor (not shown) is attached, and subsequent anchors are then attached, ending in a final orterminal anchor710. Atether718 is then cinched, to apply force between the attached anchors (hollow arrow), thus cinching the valve annulus VA. Tether718 is then typically attached by any suitable means toterminal anchor710 and then cut or otherwise detached proximal to theterminal anchor710, leaving the cinched, tethered anchors in place, attached to the valve annulus VA. To relieve some of the tension placed onterminal anchor710 and/or to provide additional attachment/anchoring strength to the terminal end of the tethered anchors, one ormore locking members714 may be deployed at or near the terminal end. For example, in oneembodiment locking member714 comprises a cylinder slidably disposed overtether718, withprongs712 extending from one end of the cylinder. Lockingmember714 is deployed out of the distal end of a termination catheter, guide catheter or the like (not shown) and is then slid alongtether718, such thatprongs712 contact and enter into valve annulus tissue VA. In one embodiment, apusher member716, such as a ball slidably disposed overtether718, may be used to push lockingmember714 forward and into engagement with tissue, as shown inFIG. 13B and as designated by solid tipped arrows. In some embodiments, lockingmember714 engages withterminal anchor710, as shown inFIGS. 13B and 13C, though such engagement is not required. Once lockingmember714 is fully engaged with valve tissue VA,tether718 is cut proximal to lockingmember714. In some embodiments,pusher member716 remains in place, while in others it may be removed before cuttingtether718.
• 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 theterminal anchor710. 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 theterminal anchor710 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.
• FIGS. 14A-14F demonstrate a method for advancing an anchor delivery device to a position for treating a mitral valve MV. The mitral valve MV, including mitral valve leaflets MVL are represented diagrammatically from an inferior perspective looking up, to depict a method for delivering a device intosubannular space552. InFIG. 14A,first guide catheter550 is show extending up to or intosubannular space552, as inFIG. 11. As shown inFIG. 14B, in one method asecond guide catheter554 may be advanced throughfirst guide catheter550 to pass through/alongsubannular space554. Thissecond guide catheter554 is steerable in one embodiment, as will be described further below, to help conformsecond guide catheter554 tosubannular space552.
• Next, as inFIG. 14C, aguide sheath556 may be passed oversecond guide catheter554 to extend along subannular space.Sheath556 is generally a flexible, tubular member that can be passed oversecond guide catheter554 and withinfirst guide catheter550. To enhance passage and exchange, any of these and other described catheter members, sheath members, or the like may be manufactured from and/or coated with one or more friction resistant materials. Oncesheath556 is in place,second guide catheter554 may be withdrawn, as shown inFIG. 14D. As shown inFIG. 14E, ananchor delivery device558 may then be advanced throughsheath556 to a position for treating the mitral valve MV.Sheath556 may then be withdrawn, as inFIG. 14F, leavinganchor delivery device558 in place for performing a treatment. A valve annulus treatment may be performed, as described extensively above, andanchor delivery device558 may be withdrawn. In some embodiments,anchor delivery device558 is used to treat one portion of the valve annulus and is then moved to another portion, typically the opposite side, to treat the other portion of the annulus. In such embodiments, any one or more of the steps just described may be repeated. In some embodiments,anchor delivery device558 is withdrawn throughfirst guide catheter550, andfirst guide catheter550 is then withdrawn. In alternative embodiments,first guide catheter550 may be withdrawn beforeanchor delivery device558.
• In various embodiments, alternative means may be used to urgeanchor delivery device558 into contact with the valve annulus. For example, in one embodiment an expandable member is coupled withanchor delivery device558 and expanded within thesubannular space552. In an alternative embodiment, a magnet may be coupled withanchor delivery device558, 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 theanchor delivery device558 into greater contact with the annulus. In another embodiment,anchor delivery device558 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 causingdevice558 to be urged against the annulus. In one embodiment, for example, the radius of curvature ofdevice558 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 theanchor delivery device558 or separate from thedevice558. In some embodiments, anchors may be driven through a strip of detachable, biocompatible material, such as Dacron, that is coupled withanchor delivery device558 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 theguide sheath556, and guidesheath556 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 toFIGS. 15A and 15B, one embodiment of asteerable catheter device560 is shown.Steerable catheter device560 may be used in a method such as that just described in reference toFIGS. 14A-14F, for example in performing a function similar to that performed bysecond guide catheter554. In other embodiments,catheter device560 may perform any other suitable function. As shown,catheter device560 suitably includes an elongate catheter body having aproximal portion562 and adistal portion564. At least one tensioningmember568, such as but not limited to a tensioning cord, extends fromproximal portion562 todistal portion564 and is coupled with thedistal portion564 and at least onetensioning actuator570/572 on the proximal portion.Tensioning actuator570/572 may include, for example, aknob570 and abarrel572 for wrapping and unwrappingtensioning member568 to apply and remove tension. Tensioningmember568 is coupled withdistal portion564 at one or more connection points580. In some embodiments,catheter device560 includes aproximal housing571, handle or the like, coupled to the proximal end ofproximal portion562 via ahub576 or other means.Housing571 may be coupled withtensioning actuator570/572 and may include one ormore arms574 for infusing fluid or for other functions. In the embodiment shown,arm574 andhousing571 include alumen567 that is in fluid communication with afluid lumen566 of the catheter body. Fluid may be introduced througharm574 to pass throughfluid lumen566 to provide, for example, for contrast material at the distal tip ofcatheter device560 to enhance visualization ofdevice560 during a procedure. Any other suitable fluid(s) may be passed throughlumens567/566 for any other purpose. Anotherlumen578 may be included indistal portion564, through which tensioningmember568 passes before attaching at a distal location alongdistal portion564.
• FIG. 15B showscatheter device560 in a deformed/bent configuration, after tension has been applied todistal portion564 by applying tension to tensioningmember568, viaknob570 andbarrel572. The bend indistal portion564 will allow it to conform more readily to a valve annulus, whilecatheter device560 in its straight configuration will be more amenable to passage through vasculature of the patient. Tensioningmember568 may be manufactured from any suitable material or combination of materials, such as but not limited to Nitinol, polyester, nylon, polypropylene and/or other polymers. Some embodiments may include two ormore tensioning members568 and/or two ormore tensioning actuators570/572 to provide for changes in shape ofdistal portion564 in multiple directions. In alternative embodiments,knob570 andbarrel572 may be substituted with any suitable devices, such as a pull cord, button, lever or other actuator. Various alternatives may also be substituted for tensioningmember568 in various embodiments. For example, shaped expandable members, shape memory members and/or the like may be used to change the shape ofdistal portion564.
• Generally,proximal portion562 of the catheter body is less flexible thandistal portion564.Proximal portion562 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 portion564 may be made of similar or other materials, but the braided material is typically not included, to provide for greater flexibility. Both proximal anddistal portions562/564 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. Eitherproximal portion562,distal portion564 or preferably both, may be made from or coated with one or more friction resistant or lubricating material to enhance passage ofdevice560 through an introducer catheter and/or to enhance passage of a sheath or other device overcatheter device560.
• With reference now toFIGS. 16A-16E, another aspect of the present invention includes improved tissue anchors for enhancing anchor attachment to valve annulus tissue. Such improved anchors typically include one or more features to help prevent the anchors from pulling out of tissue, when the anchors are placed under tension from a cinched tether, and/or to help promote tissue ingrowth of the anchors to further enhance attachment. In one embodiment, as shown inFIG. 16A, atissue anchor810 includes outwardly facinghooks812 or bends at the ends of the two arms ofanchor810. In another embodiment, as inFIG. 16B, atissue anchor820 includes inwardly facing hooks822. In a related embodiment, shown inFIG. 16D, atissue anchor840 includesmultiple bends842. In any of these embodiments, hooks812,822 or bends842 have been found to enhance attachment ofanchors810,820,840 to tissue and thus prevent anchor pullout. In another embodiment, shown inFIG. 16C, two arms of atissue anchor830 are attached at anattachment point832. Theattachment point832 may be formed by any suitable technique, such as soldering or the like. In another embodiment, as inFIG. 16E, abelt852 may be disposed over atissue anchor850 to hold the two arms of the anchor together. In either of the embodiments shown inFIGS. 16C and 16E, holding the two arms of the anchor together has be found to reduce pullout of theanchors830,850 from tissue.
• 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 toFIGS. 17A-17C, in many embodiments, self-forminganchors900 are stored in the delivery device in a straightened configuration, coupled with atether902, as shown inFIG. 17A. Basically, anchors900 are held or restrained in that straightened state, while their natural configuration is curved. Thus, when the straightenedanchor900 is released from the delivery device into tissue T, theanchor900 actually pulls itself into the tissue T, as shown inFIG. 17B, due to the storage of potential energy in the straightened state and the tendency of each of thearms901 ofanchors900 to drive the tip of the arm into the tissue as illustrated.Arms901 are joined together at ajunction903. Eacharm901 is braced against the other arm so that forces exerted by tissue T on eacharm901 are opposed by theother arm901 wherein the arms are joined to one another. This eliminates the need for an anchor driving device, such as required with staples, thus substantially simplifying the assembly and method. In addition, bracingarms901 against one another also helps to reduce or eliminate problems associated with tissue deflection. As shown by the hollow-tipped arrows inFIG. 17B, theanchor900 pulls itself into tissue T as it assumes its natural, curved shape, and exerts forces in vertical, horizontal and curved directions. Finally, after pulling itself into tissue and assuming its natural shape, as inFIG. 17C,anchor900 is fully embedded in the tissue T.
• In an alternative embodiment, as shown inFIG. 18, anchors910 may have one curved arm and one straight arm. Such ananchor910 will still pull itself into tissue T, thus embedding itself and positioning thetether912 flush with the tissue T.
• Referring now toFIG. 19A, some embodiments of a valve annulus anchor device may include anchors922, atether924, a distalforce applying member927 coupled with thetether924, atermination member926 and one or moreforce distributing sleeves920 disposed over thetether924 and between adjacent anchors922. In one embodiment, as shown, aseparate sleeve920 may be disposed between twoadjacent anchors922a,922b.Additional sleeves920 may optionally be disposed between other sets of two anchors, such asanchors922band922c. InFIG. 19A, only three anchors922 are shown for simplicity, but any number of anchors922 andsleeves920 between anchors may be used in various embodiments.Sleeve920 acts to distribute force applied between two adjacent anchors922, to help prevent such anchors922 from pulling out of tissue when force is applied totether924. Sleeve922 may be made of any suitable material, such as but not limited to metals, such as Nitinol, polymers, fabrics and the like. Sleeve922 may be a solid cylindrical member, or alternatively may have patterned cut-outs, like a stent, or be made of ribbed, woven, braided, porous, nonporous or any other suitable material, pattern, configuration or the like.Sleeve920 may be essentially rigid and axially incompressible, while in other embodiments it may be axially compressible. In one embodiment,sleeve920 may be configured as two rings, disposed adjacent two anchors922, with the rings being connected by a rod or shaft, so thattether924 is not encircled by the sleeve922.
• With reference now toFIG. 19B, in an alternative embodiment, asleeve930 may be disposed over atether934 so as to extend between more than twoanchors932. Such asleeve930 may thus distribute force applied between atermination member936 and aforce applying member937 so as to help prevent anchor pull-out from tissue. Such asleeve930 may include one or more openings through which one or more middle anchors may extend. Again,sleeve930 may have any suitable configuration, size, shape or the like and be made of any suitable material or combination of materials.Sleeve930 may extend between three, four, five or any suitable number ofanchors932 in various embodiments. In an alternative embodiment,sleeve930 may be pierced by one or more of theanchors932 and thus attached to valve annulus tissue.
• 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 (73)

1. An anchor assembly for use along a length of target tissue within a patient comprising:

a housing constructed to be passable through a blood vessel and into a heart;

the housing comprising a longitudinal axis and anchor delivery positions corresponding to anchor engagement locations along the length of the target tissue;

a series of tissue-engageable anchors removably carried by the housing, the anchors comprising a distal anchor and a proximal anchor;

the anchors being positioned at the anchor delivery positions for delivery from the housing to the length of target tissue; and

a tether coupling the anchors to one another.

2. The assembly according toclaim 1 wherein at least a portion of the housing is flexible.

3. The assembly according toclaim 2 further comprising means for urging the flexible portion of the housing from a first configuration to a second, radially outwardly expanded, curved configuration.

4. The assembly according toclaim 2 wherein the housing is steerable.

5. The assembly according toclaim 1 wherein the distal anchor is fixed to the tether and the proximal anchor is slidably coupled to the tether.

6. The assembly according toclaim 1 wherein the tether is located substantially external of the catheter-type housing.

7. The assembly according toclaim 1 wherein the anchors are self-forming and self-securing anchors.

8. The assembly according toclaim 1 wherein at least one of the anchors comprises a bioactive agent.

9. The assembly according toclaim 1 wherein at least one of the anchors comprises an electrode.

10. The assembly according toclaim 9 wherein the electrode senses at least one of impedance, temperature, and electrical signals.

11. The assembly according toclaim 9 wherein the electrode comprises an energy-application electrode to supply energy to tissue at least one of ablation and sub-ablation amounts.

12. An anchor assembly for use alone a length of target tissue within a patient comprising:

a catheter-type housing, having an open interior, constructed to be passable through a blood vessel and into a heart, at least a portion of the housing being flexible;

means for urging the flexible portion of the housing from a first configuration to a second, radially outwardly expanded, curved configuration;

a series of tissue-engageable anchors removably housed within the open interior of the housing, the anchors located at positions along the housing corresponding to anchor engagement locations along the target tissue;

the anchors being self-forming and self-securing anchors; and

a tether serially coupling the anchors to one another.

13. The assembly according toclaim 1 wherein

the anchors have a first part and a second part, the second part having a tissue-piercing tip;

the anchors are placeable in a relatively straight, undeployed state generally parallel to the longitudinal axis when carried by the housing; and

the anchors naturally assume a curved, tissue-engaging deployed state after being deployed from the housing.

14. The assembly according toclaim 1 wherein:

the housing has openings at the anchor delivery positions sized for passage of the anchors therethrough when the anchors are deployed from the housing.

15-16. (canceled)

17. The device according toclaim 13 wherein the anchors comprise said first part and at least two of said second parts extending from the first part.

18. The device according toclaim 17 wherein the second parts extend in directions generally opposite one another when in the deployed state.

19. The device according toclaim 18 wherein the second parts of said anchor have generally circular or semicircular shapes when in the deployed state.

20. The device according toclaim 13 wherein the anchors are oriented generally perpendicular to the longitudinal axis when in the deployed state.

21. The device according toclaim 13 wherein the second parts of the anchors have generally circular or semicircular shapes when in the deployed state.

22. (canceled)

23. The device according toclaim 13 wherein the housing has the diametrical dimension d and the anchors in the deployed state have ha diametrical dimension D, and wherein the ratio of D to d is at least 3.5.

24. The device according toclaim 13 wherein the housing has the diametrical dimension d and the anchors in the deployed state have a diametrical dimension D, and wherein the ratio of D to d is at least 4.4.

25. The device according toclaim 13 wherein the housing has the diametrical dimension d and the anchors in the deployed state have a diametrical dimension D, and wherein the ratio of D to d is at least 7.

26. The device according toclaim 13 wherein the housing has the diametrical dimension d and the anchors in the deployed state have a diametrical dimension D, and wherein the ratio of D to d is at least 8.8.

27. The assembly according toclaim 13 wherein the anchor comprises a bioactive agent.

28-30. (canceled)

31. The assembly according toclaim 13 wherein

the anchors comprise means for causing the tissue-piercing tips passing into tissue to secure the anchors to the tissue as the second parts move to the curved, deploy state without any further force applied to the anchor.

32-33. (canceled)

34. The assembly according toclaim 13 wherein at least some of the anchors comprise first and second of the second parts.

35. The assembly according toclaim 34 wherein at least one of the second parts comprises a hook.

36. The assembly according toclaim 34 wherein both of the second parts comprises a hook.

37. The assembly according toclaim 36 wherein the hooks extend in directions generally opposite one another when in the unrestrained state.

38-41. (canceled)

42. The assembly according toclaim 1 wherein the housing is a tubular housing.

43-50. (canceled)

51. A tissue anchor assembly for use along a length of target tissue within a patient comprising:

a plurality of anchors, each anchor comprising a base and first and second self-forming, tissue-engaging portions extending from the base, the tissue-engaging portions each comprising a tissue-piercing tip;

a housing;

the anchors located at positions along the housing corresponding to anchor engaging locations along the length of taroet tissue;

the tissue-engaging portions each movable between a curved, unrestrained state and a straightened, restrained state;

the tissue-engaging portions each having a generally circular or semicircular shape when in the unrestrained state;

a tether coupled to the bases of the anchors;

at least one said anchor being slidably coupled to the tether and another of said anchors being fastened to the tether; and

the anchors and tether being releasably mounted to the housing with the tissue-engaging portions in the restrained state, the tissue-engaging portions transferable from the restrained state to the unrestrained state when the anchors and tether are released from the housing so that the tissue-piercing tips passing into tissue secures the anchor to the tissue as the tissue-engaging portion moves to the curved, unrestrained state without any further force applied to the anchor.

52. A tissue anchor assembly comprising:

an anchor comprising a base and a resilient, self-forming, tissue-engaging portion extending from the base, the tissue-engaging portion comprising a tissue-piercing tip;

the tissue-engaging portion movable between a curved, unrestrained state and a restrained state;

a coupling element coupled to the anchor;

a housing having a centerline and a distal end;

the anchor releasably mounted to the housing with the tissue-engaging portion in the restrained state oriented generally parallel to the centerline, the tissue-engaging portion transformable from the restrained state to the unrestrained state when the anchor is released from the housing in a direction transverse to the centerline; and

the tissue-engaging portion comprising means for pulling the anchor into the tissue as the tissue-piercing tip passes into tissue and the tissue-engaging portion moves to the curved, unrestrained state.

53. The assembly according toclaim 52 wherein the tissue-engaging portion has a generally circular or semicircular shape when in the unrestrained state.

54. The assembly according toclaim 52 wherein the tissue-engaging portion is straightened when in the restrained state.

55. The assembly according toclaim 52 wherein the anchor comprises first and second of the tissue-engaging portions.

56. The assembly according toclaim 55 wherein the first tissue-engaging portion comprises a hook.

57. The assembly according toclaim 55 wherein each of the first and second tissue-engaging portions comprises a hook.

58. The assembly according toclaim 57 wherein the hooks extend in directions generally opposite one another when in the unrestrained state.

59. The assembly according toclaim 55 wherein the tissue-engaging portions extend in directions generally opposite one another when in the unrestrained state.

60. The assembly according toclaim 52 wherein the coupling element comprises a tether coupled to the base of the anchor.

61. The assembly according toclaim 60 wherein the tether is slidably coupled to the base of the anchor.

62. The assembly according toclaim 52 wherein the coupling element comprises a flexible string-like element.

63. The assembly according toclaim 60 wherein the housing is a tubular housing.

64. The assembly according toclaim 60 wherein the anchor is releasably mounted within the tubular housing.

65. The assembly according toclaim 52 wherein the hook is generally straight when in the restrained state.

66. The assembly according toclaim 52 further comprising a plurality of said anchors with the coupling element coupled to each said anchor.

67. The assembly according toclaim 66 wherein at least one said anchor is slidably coupled to the coupling element and another of said anchors is fastened to the coupling element.

68. The assembly according toclaim 52 wherein the anchor pulling means comprises means for storing potential energy when in the restrained state.

69. The assembly according toclaim 52 wherein the anchor comprises a bioactive agent.

70. The assembly according toclaim 52 wherein the anchor comprises an electrode.

71. The assembly according toclaim 70 wherein the electrode senses at least one of impedance, temperature, and electrical signals.

72. The assembly according toclaim 70 wherein the electrode comprises an energy-application electrode to supply energy to tissue at least one of ablation and sub-ablation amounts.

73. A tissue anchor assembly for use along a length of target tissue within a patient comprising:

a plurality of anchors, each anchor comprising a base and a first and second resilient, self-forming, tissue-engaging portions extending from the base, the tissue-engaging portions each comprising a tissue-piercing tip;

the tissue-engaging portions each movable between a curved, unrestrained state and a restrained state;

the tissue-engaging portions each having a generally circular or semicircular shape when in the unrestrained state;

a coupling element coupled to each of the anchors;

a tubular housing having a centerline;

the anchors releasably mounted within the housing at positions corresponding to anchor in engaging locations along a length of target tissue with the tissue-engaging portions in the restrained state, the tissue-engaging portions transformable from the restrained state to the unrestrained state when the anchors are released from the housing;

the tissue-engaging portions comprising means for pulling the anchors into the tissue as the tissue-piercing tips pass into tissue and the tissue-engaging portions move to the curved, unrestrained states; and

the anchor pulling means comprising means for storing potential energy when in the restrained state.

74. A method for securing an anchor to a length of target tissue of a patient comprising:

directing an anchor assembly, comprising an anchor carried by an anchor carrier, to a target tissue site, the anchor carrier comprising a distal end; and

releasing the anchor from the anchor carrier at a position spaced apart from the distal end, the releasing step comprising:

placing a tissue-piercing tip of the anchor into engagement with the tissue at the target tissue site; and

the anchor pulling itself into the tissue as the anchor moves from a restrained state to an unrestrained state.

75. The method according toclaim 74 wherein the anchor assembly directing step is carried out with a tubular anchor carrier releasably housing the anchor.

76. The method according toclaim 74 wherein the anchor assembly directing step is carried out with the anchor having a first part and a second part, the second part naturally assuming a curved shape when the anchor is in the unrestrained state.

77. The method according toclaim 74 wherein the anchor assembly directing step is carried out with the anchor having a first part and a second part, the second part naturally assuming a curved, generally circular or semicircular shape when the anchor is in the unrestrained state.

78. The method according toclaim 74 wherein the anchor assembly directing step is carried out with the anchor having a first part and at least two second parts, each second part naturally assuming a curved, generally circular or semicircular shape when the anchor is in the unrestrained state.

79. The method according toclaim 78 wherein the anchor pulling step comprises bracing said two second parts against one another through the first part whereby problems associated with tissue deflection are at least substantially reduced.

80. The method according toclaim 74 wherein the anchor assembly directing step is carried out with a plurality of the anchors coupled to one another by a tether, each anchor having a first part and a second part, the second part naturally assuming a curved, generally circular or semicircular shape when the anchor is in the unrestrained state.

81. The method according toclaim 74 wherein the anchor assembly directing step is carried out with a plurality of the anchors coupled to one another by a tether, each anchor having a first part and at least two second parts, each second part naturally assuming a curved, generally circular or semicircular shape when the anchor is in the unrestrained state.

82. The method according toclaim 74 wherein the directing step is carried out with an anchor comprising a bioactive agent.

83. The method according toclaim 74 wherein the directing step is carried out with an anchor comprising an electrode.

84. The method according toclaim 83 further comprising sensing, through the electrode, at least one of impedance, temperature, and electrical signals.

85. The method according toclaim 83 further comprising supplying the electrode energy in at least one of ablation and sub-ablation amounts.

86. The method according toclaim 74 wherein the anchor assembly directing step is carried out with a plurality of the anchors coupled to one another by a tether, and further comprising simultaneously positioning the anchors at positions along the length of target tissue prior to the releasing step.

87. The assembly according toclaim 1 wherein the housing is a catheter-type housing having an open interior and the anchors are removably housed within the housing interior.

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