Fixation devices, systems and methods for engaging tissue

Abstract

The invention provides devices, systems and methods for tissue approximation and repair at treatment sites. The devices, systems and methods of the invention will find use in a variety of therapeutic procedures, including endovascular, minimally-invasive, and open surgical procedures, and can be used in various anatomical regions, including the abdomen, thorax, cardiovascular system, heart, intestinal tract, stomach, urinary tract, bladder, lung, and other organs, vessels, and tissues. The invention is particularly useful in those procedures requiring minimally-invasive or endovascular access to remote tissue locations, where the instruments utilized must negotiate long, narrow, and tortuous pathways to the treatment site. In addition, many of the devices and systems of the invention are adapted to be reversible and removable from the patient at any point without interference with or trauma to internal tissues.

What is claimed is: 
     
         1 . A fixation system for engaging leaflets of a heart valve comprising:
 a catheter having an elongated shaft, a proximal end and a distal end, the catheter configured to pass from remote vasculature of a patient to a location within the patient's body near the leaflets; and a fixation device detachably coupled to the distal end of the catheter;   a central spacer of the fixation device having engagement portions for engaging the leaflets, the spacer configured to be disposed between the leaflets when the leaflets are engaged;   a pair of clasping elements movably integrated with the fixation device, each clasping element moveable with respect to one of the engagement portions and configured to be moved into opposition with one of the engagement portions so as to capture a leaflet therebetween, each clasping element being cantilevered from the fixation device and resiliently biased to move toward one of the engagement portions of the central spacer; and   an actuator configured to move the pair of clasping elements to a first position where the clasping elements are distant from a corresponding one of the engagement portions of the central spacer and a second position where the clasping elements abut a corresponding one of the engagement portions of the central spacer to capture a corresponding leaflet.   
     
     
         2 . The fixation system according to  claim 1 , wherein the actuator comprises a line or a rod, and the actuator moves the pair of clasping elements to the first position in response to tension being applied to the wire or rod. 
     
     
         3 . The fixation system according to  claim 1 , wherein the resilient biasing of the clasping elements moves the pair of clasping elements to the second position when the tension on the line or rod is released. 
     
     
         4 . The fixation system according to  claim 1 , wherein the clasping elements have frictional features configured to enhance grip on the leaflet engaged thereby. 
     
     
         5 . The fixation system according to  claim 1 , wherein the fixation device is configured to be removed from the catheter by actuating an actuator at the proximal end of the catheter to uncouple the fixation device from the distal end of the catheter. 
     
     
         6 . The fixation system according to  claim 1 , wherein the clasping elements are approximately parallel to each other in second position. 
     
     
         7 . The fixation system according to  claim 1 , wherein the engagement portions of the central spacer are curved surfaces. 
     
     
         8 . The fixation system according to  claim 1 , further comprising a locking mechanism adapted to lock the fixation device in the second position. 
     
     
         9 . The fixation system according to  claim 8 , further comprising an unlocking mechanism adapted to unlock the fixation device so as to be movable from the second position. 
     
     
         10 . The fixation system according to  claim 1 , wherein the clasping elements have frictional features configured to enhance grip on the leaflet engaged thereby. 
     
     
         11 . The fixation system according to  claim 1 , wherein the clasping elements are configured to perform independent clasping of different heart valve leaflets. 
     
     
         12 . The fixation system according to  claim 1  further comprising a coupling member for detachably coupling the fixation device to the catheter. 
     
     
         13 . The system according to  claim 1 , wherein the coupling member is configured to detach the fixation device from the catheter using an actuator at the proximal end of the catheter. 
     
     
         14 . The system according to  claim 1 , wherein the central spacer comprises a column disposed between the clasping elements. 
     
     
         15 . The system according to  claim 1 , wherein the engagement portions comprise different sides of the column. 
     
     
         16 . The system according to  claim 1 , further comprising a covering that covers at least a portion of the fixation device, the covering configured to promote tissue ingrowth. 
     
     
         17 . The system according to  claim 15 , wherein the covering comprises a biocompatible material in the form of at least one of a fabric, mesh, textured weave, felt, looped or porous structure. 
     
     
         18 . A fixation system for engaging leaflets of a heart valve comprising:
 a catheter having an elongated shaft, a proximal end and a distal end, the catheter configured to pass from remote vasculature of a patient to a location within the patient's body near the leaflets; and a fixation device removably coupled to the distal end of the catheter;   a spacer on the fixation device configured to be disposed between engaged leaflets;   a pair of clasping elements movably integrated with the fixation device, the each clasping elements moveable with respect to the spacer and configured to be moved into opposition with the spacer so as to capture each of the leaflets between the spacer and a corresponding one of the clasping elements, each clasping element being pivotally integrated with the spacer; and   an actuator configured to move the pair of clasping elements to a first position distant from the spacer and a second position where the clasping elements abut the spacer to capture the leaflets therebetween.   
     
     
         19 . The fixation system according to  claim 18 , wherein the clasping elements are configured to pivot from the second position where the clasping elements are substantially parallel to an open position where the clasping elements have at least a 270 degree separation angle. 
     
     
         20 . The fixation system according to  claim 19 , wherein the clasping elements are configured to pivot to a 360 degree separation angle. 
     
     
         21 . The fixation system according to  claim 18 , wherein the actuator comprises a rod. 
     
     
         22 . The fixation system according to  claim 21 , wherein the rod is connected to an actuator mechanism that connects the rod to the clasping elements, the actuator mechanism configured to move the pair of clasping elements away from the spacer when the rod is extended distally, and to move the pair of clasping element toward the second position when the rod is retracted proximally. 
     
     
         23 . The fixation system according to  claim 21 , wherein the actuator mechanism is rotatably coupled to the rod and the clasping elements 
     
     
         24 . The fixation system according to  claim 18 , wherein the clasping elements are longer in length than the spacer. 
     
     
         25 . The fixation system according to  claim 24 , where the clasping elements extend in the proximal direction further than the spacer extends in the proximal direction when in the second position. 
     
     
         26 . The fixation system according to  claim 18 , wherein the clasping elements comprise convexly curved surfaces. 
     
     
         27 . The fixation system according to  claim 26 , wherein the spacer is at least partially recessed within a corresponding one of the clasping elements in the second position. 
     
     
         28 . The fixation system according to  claim 18 , wherein the clasping elements have frictional features configured to enhance grip on tissue engaged thereby. 
     
     
         29 . The fixation system according to  claim 18 , wherein the clasping elements are configured to perform independent clasping of different heart valve leaflets. 
     
     
         30 . The fixation system according to  claim 18 , further comprising a coupling member for detachably coupling the fixation device to the catheter. 
     
     
         31 . The fixation system according to  claim 18 , wherein the coupling member is configured to detach the fixation device from the catheter using an actuator at the proximal end of the catheter. 
     
     
         32 . The fixation system according to  claim 18 , wherein the actuator comprises a rod extending through the spacer, the actuator rod coupled to the pair of clasping elements by a pair of arms, wherein the pair of clasping elements are configured to move away from the spacer in response to the rod being extended distally through the spacer, and move toward the spacer in response to the rod being retracted proximally through the spacer. 
     
     
         33 . The system according to  claim 18 , wherein the spacer comprises a column disposed between the clasping elements. 
     
     
         34 . The system according to  claim 18 , further comprising a covering that covers at least a portion of the fixation device, the covering configured to promote tissue ingrowth. 
     
     
         35 . The system according to  claim 34 , wherein the covering comprises a biocompatible material in the form of at least one of a fabric, mesh, textured weave, felt, looped or porous structure.