Abstract:
A tissue shaping device adapted to be deployed in a lumen to modify the shape of target tissue adjacent to the lumen. In one embodiment the device includes first and second anchors; a connector disposed between the first and second anchors; and a focal deflector disposed between the first and second anchors and may be adapted to extend away from the lumen axis and toward the target tissue and/or away from the lumen axis and away from the target tissue when the device is deployed in the lumen. The invention is also a method of modifying target tissue shape. The method includes the steps of providing a tissue shaping device comprising proximal and distal anchors, a connector disposed between the proximal and distal anchors, and a focal deflector; placing the tissue shaping device in a lumen adjacent the target tissue; applying a shaping force from the focal deflector against a lumen wall to modify the shape of the target tissue; and expanding the proximal and distal anchors to anchor the device in the lumen.

Description:
CROSS-REFERENCE  
       [0001]     This application claims the benefit of U.S. Provisional Application No. 60/476,693, filed Jun. 5, 2003, which application is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The mitral valve is a portion of the heart that is located between the chambers of the left atrium and the left ventricle. When the left ventricle contracts to pump blood throughout the body, the mitral valve closes to prevent the blood from being pumped back into the left atrium. In some patients, whether due to genetic malformation, disease or injury, the mitral valve fails to close properly causing a condition known as regurgitation, whereby blood is pumped into the atrium upon each contraction of the heart muscle. Regurgitation is a serious, often rapidly deteriorating, condition that reduces circulatory efficiency and must be corrected.  
         [0003]     Two of the more common techniques for restoring the function of a damaged mitral valve are to surgically repair the valve, replace the valve with a mechanical valve, or to suture a flexible ring around the valve to support it. Each of these procedures is highly invasive because access to the heart is obtained through an opening in the patient&#39;s chest. Patients with mitral valve regurgitation are often relatively frail thereby increasing the risks associated with such an operation.  
         [0004]     One less invasive approach for aiding the closure of the mitral valve involves the placement of a support structure in the cardiac sinus and vessel that passes adjacent the mitral valve. The support structure is designed to push the vessel and surrounding tissue against the valve to aid its closure. This technique has the advantage over other methods of mitral valve repair because it can be performed percutaneously without opening the chest wall. Examples of such devices are shown in U.S. patent application Ser. No. 10/003,910, “Focused Compression Mitral Valve Device and Method;” U.S. patent application Ser. No. 10/142,637, “Body Lumen Device Anchor, Device and Assembly;” U.S. patent application Ser. No. 10/331,143, “System and Method to Effect the Mitral Valve Annulus of a Heart;” and U.S. patent application Ser. No. 10/429,172, “Device and Method for Modifying the Shape of a Body Organ,” filed May 2, 2003. The disclosures of these patent applications are incorporated herein by reference.  
         [0005]     The purpose of a support device in a lumen such as a vein or artery is to reshape a particular tissue area adjacent to the lumen. In order to be minimally invasive, the reshaping should be limited to the target tissue, such as the mitral valve annulus, and any reshaping of other tissue adjacent to the lumen should be minimized or avoided. For example, to treat mitral valve regurgitation, the device is placed in the coronary sinus to reshape the mitral valve annulus. Care should be taken to minimize the reshaping of other adjacent tissue, such as nearby arteries. See, e.g., the following applications (the disclosures of which are incorporated herein by reference): U.S. patent application Ser. No. 09/855,945, “Mitral Valve Therapy Device, System and Method” (published Nov. 14, 2002, as U.S. 2002/0169504 A1); U.S. patent application Ser. No. 09/855,946, “Mitral Valve Therapy Assembly and Method” (published Nov. 14, 2002, as U.S. 2002/0169502 A1). It is also advisable to monitor cardiac perfusion during and after such mitral valve regurgitation therapy. See, e.g., U.S. patent application Ser. No. 10/366,585, “Method of Implanting a Mitral Valve Therapy Device,” the disclosure of which is incorporated herein by reference.  
       SUMMARY OF THE INVENTION  
       [0006]     One aspect of the invention is a tissue shaping device adapted to be deployed in a lumen to modify the shape of target tissue adjacent to the lumen. In one embodiment the device includes first and second anchors; a connector disposed between the first and second anchors; and a focal deflector disposed between the first and second anchors and may be adapted to extend away from the lumen axis and toward the target tissue and/or away from the lumen axis and away from the target tissue when the device is deployed in the lumen. The focal deflector may have an expandable portion that is, e.g., self-expanding or expandable through the application of an actuation force. The device may also have a lock to lock the focal deflector in an expanded configuration.  
         [0007]     In some embodiments the focal deflector is integral with the connector. For example, the focal deflector may be a bend in the connector, such as a bend that extends away from the lumen axis and toward the target tissue. The focal deflector may include a local change to the linear shape of the connector, such as a portion of increased curve of the curved line of the connector. The focal deflector may also include a flattened portion of the connector.  
         [0008]     In some embodiments the focal deflector includes an expandable anchor and possibly a portion integral with the connector and adapted to extend away from the lumen axis and toward the target tissue when the device is deployed in the lumen.  
         [0009]     Another aspect of the invention is a method of modifying target tissue shape. The method includes the steps of providing a tissue shaping device comprising proximal and distal anchors, a connector disposed between the proximal and distal anchors, and a focal deflector; placing the tissue shaping device in a lumen adjacent the target tissue; applying a shaping force from the focal deflector against a lumen wall to modify the shape of the target tissue; and expanding the proximal and distal anchors to anchor the device in the lumen. In some embodiments the expanding step includes the steps of expanding the distal anchor to anchor within the lumen; applying a proximally directed force on the device; and expanding the proximal anchor while applying the proximally directed force.  
         [0010]     In some embodiments, the placing step includes the step of orienting the focal deflector away from the lumen axis and toward the target tissue. In other embodiments, the placing step includes the step of orienting the focal deflector away from the lumen axis and away from the target tissue.  
         [0011]     The applying step may include the step of expanding the focal deflector, such as by applying an actuation force to the focal deflector. The focal deflector may also be locked in its expanded configuration. In some embodiments the applying and expanding steps may include expanding the distal anchor to anchor within the lumen; applying a proximally directed force on the device; expanding the focal deflector while applying the proximally directed force; applying a proximally directed force on the device after expanding the focal deflector; and expanding the proximal anchor while applying the proximally directed force of the previous step.  
         [0012]     Yet another aspect of the invention is a tissue shaping device adapted to be deployed in a lumen to modify the shape of target tissue adjacent to the lumen. In some embodiments the device includes an expandable anchor; a focal deflector; a connector disposed between the anchor and the focal deflector; and a tail extending from the focal deflector away from the anchor. The focal deflector may include an expandable portion. In some embodiments, the focal deflector is adapted to extend away from the lumen axis and away from the target tissue when the device is deployed in the lumen.  
         [0013]     One application for the device of this invention is in the treatment of mitral valve regurgitation. The invention will be described in further detail below with reference to the drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]      FIG. 1  shows a tissue reshaping device according to one aspect of the invention deployed in a coronary sinus to reshape the mitral valve annulus to treat mitral valve regurgitation.  
         [0015]      FIG. 2  is a perspective view of the device shown in  FIG. 1 .  
         [0016]      FIG. 3  shows another embodiment of the invention.  
         [0017]      FIG. 4  shows another embodiment of the invention and its use to treat mitral valve regurgitation.  
         [0018]      FIG. 5  is a perspective view of the device shown in  FIG. 4 .  
         [0019]      FIG. 6  shows an embodiment in which the focal deflector faces in the same direction as the anchors.  
         [0020]      FIG. 7  shows yet another embodiment of the invention deployed in a coronary sinus to reshape the mitral valve annulus to treat mitral valve regurgitation.  
         [0021]      FIG. 8  is a perspective view of the device shown in  FIG. 7 .  
         [0022]      FIG. 9  shows yet another embodiment of the invention.  
         [0023]      FIG. 10  shows still another embodiment of the invention.  
         [0024]      FIG. 11  shows the focal deflector of the embodiment of  FIG. 10 .  
         [0025]      FIG. 12  is yet another view of the focal deflector of the embodiment of  FIG. 10 .  
         [0026]      FIG. 13  shows yet another embodiment of the invention.  
         [0027]      FIG. 14  shows an embodiment of the invention with a tail portion extending from the focal deflector. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0028]     Tissue shaping devices that apply force to a localized, discrete portion of the vessel wall surrounding a lumen have been described. See, e.g., U.S. patent application Ser. No. 10/003,910, “Focused Compression Mitral Valve Device and Method,” which describes the use of such devices disposed in the coronary sinus to treat mitral valve regurgitation. Other therapies deploy one or more rigid devices in the lumen to change the shape of the lumen and adjacent tissue. See, e.g., Lashinski et al. U.S. patent application Ser. No. 10/066,302 (published as U.S. 2002/0151961 A1); Taylor et al. U.S. patent application Ser. No. 10/068,264 (published as U.S. 2002/0183835 A1); Liddicoat et al. U.S. patent application Ser. No. 10/112,354 (published as U.S. 2002/0183838 A1); the disclosures of which are incorporated herein by reference. Still other tissue shaping devices utilize an “anchor and cinch” method to modify tissue adjacent a lumen, i.e., by anchoring a distal anchor, placing a proximally-directed force on a connector extending proximally from the distal anchor, and anchoring a proximal anchor before ceasing the proximally directed force to maintain the device&#39;s configuration and the reshaping of the tissue.  
         [0029]     The present invention provides a device disposed in a lumen to reshape tissue adjacent to the lumen that includes a focal deflector tissue reshaper, two anchors and an optional connector to help maintain the position of the focal tissue reshaper within the lumen. The use of a focal deflector tissue reshaper aimed at target tissue adjacent to the lumen minimizes the risk of adverse consequences from altering the shape of non-target tissue adjacent to other parts of the lumen. The anchors and/or connector may also be used to help reshape the target tissue.  
         [0030]      FIGS. 1 and 2  show a tissue reshaping device  10  according to one aspect of this invention. Device  10  is designed to be disposed in the coronary sinus or other cardiac vein to treat mitral valve regurgitation. It should be understood that such devices may also be used in other body lumens to reshape other tissue.  
         [0031]     As shown in  FIGS. 1 and 2 , device  10  has a proximal anchor  12  and a distal anchor  14  connected by a connector  15 . In the embodiment shown in  FIGS. 1 and 2 , the anchors  12  and  14  are formed from metal wire, preferably made from a shape memory material such as nitinol, bent into a figure 8 configuration. Crimps  16  and  18  hold the wire in place and attach the anchors to connector  15 . In the embodiment shown in  FIG. 1 , crimps  16  and  18  are formed from wound wire, such as nitinol. In the embodiment shown in  FIG. 2 , crimps  16  and  18  are formed from metal tubes, such as titanium tubes.  
         [0032]     Device  10  is delivered via a catheter to the treatment site within the lumen in a collapsed or unexpanded configuration. After expelling device  10  from the catheter at the treatment site (either by advancing the device distally out of the end of the catheter or by moving the end of the catheter proximally while maintaining the device stationary), the device&#39;s anchors begin to self-expand. At the proximal end of each anchor is an eyelet  20  and  22 . Advancing eyelets  20  and  22  distally over corresponding lock bumps  24  and  26  further expands and locks the anchors  12  and  14  in an expanded configuration. Further details of the construction, delivery and deployment of such anchors may be found in U.S. patent application Ser. No. 10/142,637, “Body Lumen Device Anchor, Device and Assembly;” U.S. patent application Ser. No. 10/331,143, “System and Method to Effect the Mitral Valve Annulus of a Heart;” and U.S. patent application Ser. No. 10/429,172, “Device and Method for Modifying the Shape of a Body Organ,” filed May 2, 2003. It should be understood that other anchor designs could be used without departing from the invention.  
         [0033]     Device  10  has a focal deflector  28  facing away from the anchors  12  and  14  and toward the mitral valve annulus. In this embodiment, focal deflector  28  is formed as a bend in the connector  15 . As shown in  FIG. 1 , when disposed in lumen  30  (shown here as the coronary sinus), the orientation of device  10  places focal deflector  28  against the target tissue  37  to reshape the mitral valve annulus  38 . Device  10  may be curved to help ensure this orientation. For delivery via a catheter, focal deflector  28  is deformed and assumes the shape shown in  FIGS. 1 and 2  after deployment from the catheter.  
         [0034]     Because of the action of focal deflector  28 , the desired reshaping of the mitral valve annulus may be achieved with less cinching than other device designs or even with no cinching. Thus, the anchors do not need to anchor as tightly and may be expanded less, thereby minimizing the reshaping of non-target tissue adjacent the anchors. In addition, with less or no cinching, any undesirable effect on non-target tissue adjacent the connector is also minimized. On the other hand, should reshaping adjacent to the anchors and/or connector be desired, such reshaping can be achieved through a combination of expansion of the anchors and cinching of the connector between them. The cinching is performed as with prior devices: by anchoring a distal anchor, placing a proximally-directed force on a connector extending proximally from the distal anchor, and anchoring a proximal anchor before ceasing the proximally directed force to maintain the device&#39;s configuration and the reshaping of the tissue.  
         [0035]      FIG. 3  shows another embodiment of the invention. As in the embodiment of  FIGS. 1 and 2 , device  40  in  FIG. 3  has two anchors  42  and  44  connected by a connector  46 . Connector  46  is formed as a ribbon, preferably from a shape memory material such as nitinol, with a focal deflector  48  formed therein. The anchors  42  and  44  may be formed like the anchors of the previous embodiment.  
         [0036]     In use, device  40  is delivered via catheter to the treatment site in a collapsed or unexpanded configuration. Device  40  is then deployed by expelling it from the catheter and expanding it within a lumen in a position and orientation that places focal deflector  48  against the lumen&#39;s vessel wall adjacent to the target tissue to modify the shape of the target tissue. While the device may also be cinched to provide additional reshaping, the amount of cinching required will be less, thereby minimizing the reshaping of any non-target tissue adjacent the lumen by the connector. In addition, as with the previous embodiment, anchors  42  and  44  do not need to be expanded as much, thereby minimizing the reshaping of the non-target tissue adjacent to the anchors.  
         [0037]      FIGS. 4 and 5  show yet another embodiment of the invention and its use to treat mitral valve regurgitation. Device  50  has proximal and distal anchors  52  and  54  connected by a connector  56 . Anchors  52  and  54  are preferably formed like the anchors of the embodiments of  FIGS. 1-3 .  
         [0038]     A focal deflector  58  is disposed on connector  56 . In this embodiment, focal deflector  58  has substantially the same design as anchors  52  and  54 . Focal deflector  58  is formed from wire (preferably made from a shape memory material such as nitinol) and has a figure 8 configuration when expanded. A crimp  62  attaches the wire to the connector  56 . The anchors and focal deflector are delivered via a catheter to the appropriate site within the lumen in an unexpanded configuration, then expanded to a deployed configuration through the application of actuation forces delivered by catheters or other known tools. Like the anchors, focal deflector  58  may be locked in its expanded configuration by advancing an eyelet  60  over a lock bump  61 .  
         [0039]     As shown in  FIG. 4 , when disposed in a lumen such as the coronary sinus, the orientation of device  50  places focal deflector  58  against the coronary sinus wall adjacent the target tissue  59  of the mitral valve annulus  57  to reshape the mitral valve annulus. Device  50  may be curved to help ensure proper orientation. As with the other embodiments, because of the action of focal deflector  58 , the desired reshaping of the mitral valve annulus may be achieved with less or even with no cinching. Thus, the anchors do not need to anchor as tightly and may be expanded less, thereby minimizing the reshaping of non-target tissue adjacent the anchors. In addition, with less or no cinching, the effect on non-target tissue adjacent the connector is also minimized.  
         [0040]     Because it can be expanded and locked like an anchor, the focal deflector  58  of  FIGS. 4 and 5  can also be used like an anchor during a cinching operation. For example, after expanding and locking distal anchor  54 , a proximally-directed force can be exerted on the portion of connector  56  extending between distal anchor  54  and focal deflector  58  prior to expanding and locking focal deflector  58  to cinch the distal portion of device  50 . Likewise, after expanding and locking focal deflector  58 , another proximally-directed force can be exerted on the portion of connector  56  extending between focal deflector  58  and proximal anchor  52  prior to expanding and locking proximal anchor  52  to cinch the proximal portion of device  50 . If cinching is needed to achieve the desired shape modification of the target tissue, the presence of focal deflector  58  enables a user to cinch the distal and proximal portions of device  50  with different cinching forces.  
         [0041]     The focal deflector shown in the embodiment of  FIGS. 4 and 5  may have other orientations. For example,  FIG. 6  shows an embodiment in which the focal deflector  68  of device  60  faces in the same direction as the anchors  62  and  64 . In addition, the focal deflector of the embodiments of  FIGS. 4-6  may be self-expanding but not locking.  
         [0042]      FIGS. 7 and 8  show yet another embodiment of the invention. Like the other embodiments, device  70  has a proximal anchor  72  and a distal anchor  74  connected by a connector  76 . Disposed on connector  76  is a focal deflector  78  formed as an expanded cut-out tube, such as a modified stent.  
         [0043]     As shown in  FIG. 7 , device  70  may be deployed in the coronary sinus to treat mitral valve regurgitation by reshaping the tissue adjacent to focal deflector  78 . Device  70  is delivered to in an expanded configuration to the treatment site, then expelled from the catheter. Anchors  72  and  74  self-expand, then are further expanded and locked as in the other embodiments. Focal deflector  78  may also self-expand to the configuration shown in  FIGS. 7 and 8 . Alternatively, focal deflector  78  may be expanded by using a balloon catheter to provide the actuation force, as is well-known in the stent art.  
         [0044]     As in the other embodiments, because of the action of focal deflector  78 , the desired reshaping of the mitral valve annulus may be achieved with less or even with no cinching. Thus, the anchors do not need to anchor as tightly and may be expanded less, thereby minimizing the reshaping of non-target tissue adjacent the anchors. In addition, with less or no cinching, the effect on non-target tissue adjacent the connector is also minimized.  
         [0045]      FIG. 9  shows an embodiment of a device  80  with proximal and distal anchors  82  and  84  with a figure 8 design like other embodiments connected by a connector  86 . A focal deflector  88  is formed as a flattened area in connector  86 . In this embodiment, connector  86  and focal deflector  88  are formed from shape memory material wire, such as nitinol. While  FIG. 9  shows connector  86  and focal deflector  88  as three discrete straight segments, any or all of these elements may be have a curve. In any variation on the embodiment of  FIG. 9 , however, the focal deflector  88  is straighter than the connector portions extending distally and proximally from it to the distal and proximal anchors, respectively. Device  80  may be delivered and deployed at the treatment site in the same manner as the embodiments described above.  
         [0046]      FIGS. 10-12  show yet another embodiment of a device  90  with proximal and distal anchors  92  and  94  with a figure 8 design like other embodiments connected by a connector  96 . A focal deflector  98  is also formed with a wire  100  (preferably made from a shape memory material such as nitinol) bent into a figure 8 pattern. As shown in more detail in  FIGS. 11 and 12 , instead of a wrapped wire or solid metal crimp, focal deflector  98  has a base  102  with two downwardly extending struts  104 . The angular spread between struts  104  helps orient the device within the lumen. Base  102  may be made from a laser-cut shape memory material such as nitinol. The combination of the expansion of anchor wire  100  (as in the embodiment shown in  FIG. 6 ) with the downward pressure from struts  104  (as in the embodiments shown in  FIGS. 1-3 ) provide for focal deflection of target tissue adjacent to the focal deflector.  
         [0047]     As with other embodiments, device  90  may be delivered via a catheter and deployed in the coronary sinus to treat mitral valve regurgitation by reshaping the tissue adjacent to focal deflector  98 . The device is in a deformed and unexpanded state within the catheter, and self-expands and reforms into the shape shown in  FIG. 10  once expelled from the catheter. The anchors  92  and  94  and the anchor portion  100  of focal deflector  98  are further expanded and locked by advancing their respective eyelets over corresponding lock bumps on their proximal sides.  
         [0048]     Because of the action of focal deflector  98 , the desired reshaping of the mitral valve annulus may be achieved with less or even with no cinching. Thus, the anchors  92  and  94  do not need to anchor as tightly and may be expanded less, thereby minimizing the reshaping of non-target tissue adjacent the anchors. In addition, with less or no cinching, the effect on non-target tissue adjacent the connector is also minimized. Furthermore, because focal deflector  98  is formed similar to an anchor, the presence of focal deflector  98  enables a user to cinch the distal and proximal portions of device  90  with different cinching forces.  
         [0049]     The embodiment of  FIG. 13  omits the wire  100  of focal deflector  98  but is identical to the embodiment of  FIGS. 10-12  in all other respects.  
         [0050]      FIG. 14  shows an embodiment of a device  110  with a proximal anchor  112  formed in a figure 8 pattern, as in other embodiments. A focal deflector  114  formed as an anchor in a figure 8 pattern, as in the embodiment of  FIG. 6 , is connected to proximal anchor  112  by a connector  116 . A tail  118  extends distally from focal deflector  114  formed from a wire bent in a loop. The loop has a circumference that allows the loop to engage the wall of the vessel in which the device is placed. The points of engagement between the loop and vessel depend on the relative diameters of the loop and vessel. When deployed in a curved vessel, such as the coronary sinus, the loop will follow the vessel&#39;s curve to orient the device correctly within the vessel. The ends of the wire are contained with a crimp  120 . A small loop  122  is formed at the distal end of tail  118  to provide additional spring action to the tail.  
         [0051]     As in the other embodiments, device  110  may be delivered via a catheter and deployed in the coronary sinus to treat mitral valve regurgitation by reshaping the tissue adjacent to focal deflector  114 . The device is in a deformed and unexpanded state within the catheter, and self-expands and reforms into the shape shown in  FIG. 14  once expelled from the catheter. The proximal anchor  112  and focal deflector  114  are further expanded and locked by advancing their respective eyelets over corresponding lock bumps on their proximal sides.  
         [0052]     Element  114  of device  110  in  FIG. 14  may be used as a distal anchor instead of as a focal deflector, of course.  
         [0053]     Other modifications of the device are within the scope of the invention. For example, the anchors may be of some other design known in the art. In addition, the focal deflector may have some other shape designed to make the desired change in the target tissue.