Apparatus for grasping and cinching tissue anchors

Abstract

Methods and apparatus for controlled grasping and cinching or locking of a tissue anchor are provided. In one variation, a tube is provided having a lumen and a resilient member that obstructs the lumen. A grasper may be advanced coaxially through the lumen, such that it reversibly displaces the resilient member and extends beyond the lumen's outlet to engage an element of the tissue anchor. The grasper then may be retracted within the tube, such that the resilient member again obstructs the lumen of the tube. Continued retraction of the grasper may act to cinch the anchor, for example, via interaction between the anchor and the obstructing resilient member. During cinching, a cinching mechanism of the anchor optionally may be positioned at least partially within the tube to enhance lateral stability. Furthermore, feedback indicative of a degree of cinching or locking may be provided during cinching.

1 . An apparatus for securing a tissue anchor, the apparatus comprising:
 a tubular member defining a lumen therethrough with a distal outlet; and   at least one resilient member that at least partially obstructs the lumen proximal of the distal outlet such that a distal compartment within the tube is defined between the at least one obstructing resilient member and the distal outlet, wherein the obstructing resilient member is adapted to be reversibly displaced from the lumen when displaced by a grasper.   
   
   
       2 . The apparatus of  claim 1 , further comprising a grasper configured for coaxial advancement through the lumen, wherein the grasper is configured to extend beyond the distal outlet of the lumen to grasp the tissue anchor or a portion thereof. 
   
   
       3 . The apparatus of  claim 1 , wherein the tubular member is rigid. 
   
   
       4 . The apparatus of  claim 1 , wherein the tubular member is flexible along at least a portion of its length. 
   
   
       5 . The apparatus of  claim 1 , wherein the apparatus is configured to cinch the tissue anchor with the at least one resilient member. 
   
   
       6 . The apparatus of  claim 1 , further comprising a cinching mechanism adapted to cinch the tissue anchor when the anchor is urged against the at least one resilient member. 
   
   
       7 . The apparatus of  claim 6 , wherein the distal compartment within the tubular member is adapted to at least partially receive the cinching mechanism therein during cinching of the tissue anchor such that the cinching mechanism is laterally stabilized relative to the tubular member. 
   
   
       8 . The apparatus of  claim 1 , wherein the tubular member defines at least one slot in communication with the lumen and wherein the at least one resilient member is disposed within the at least one slot to at least partially obstruct the lumen. 
   
   
       9 . The apparatus of  claim 1 , wherein the distal outlet defines an atraumatic inner circumferential edge. 
   
   
       10 . The apparatus of  claim 1 , further comprising a feedback element configured to indicate a degree of anchor cinching. 
   
   
       11 . The apparatus of  claim 10 , wherein the feedback element comprises a spring element. 
   
   
       12 . The apparatus of  claim 10 , further comprising a longitudinally translatable marker positioned along the tubular member for visually indicating a degree of anchor cinching. 
   
   
       13 . The apparatus of  claim 1 , wherein the apparatus comprises three obstructing resilient members positioned uniformly and circumferentially within the tubular member. 
   
   
       14 . The apparatus of  claim 1 , wherein the at least one obstructing resilient member projects radially from the lumen when displaced. 
   
   
       15 . A system for controlled cinching of a tissue anchor, the system comprising:
 a grasper adapted to engage the tissue anchor or a suture depending from the tissue anchor;   a cinching assembly defining a lumen for passage of the grasper therethrough and to cinch the engaged tissue anchor or suture against a portion of the cinching assembly; and   a force feedback mechanism configured to indicate a degree of anchor cinching force.   
   
   
       16 . The system of  claim 15 , wherein the force feedback mechanism comprises a compression spring configured to apply a restoring force during anchor cinching. 
   
   
       17 . The system of  claim 15 , wherein the force feedback mechanism comprises a longitudinally translatable marking element configured to record a maximum degree of exerted anchor cinching force. 
   
   
       18 . The system of  claim 15 , wherein the cinching assembly comprises:
 a tubular member having a lumen with a distal outlet such that the grasper is able to be advanced coaxially through the lumen, wherein a distal portion of the tubular member defines a compartment for laterally stabilizing a cinching mechanism relative to the tubular member; and   at least one resilient member that at least partially obstructs the lumen and is adapted to be reversibly displaced by the grasper when the grasper is passed beyond the distal outlet of the lumen.