Tissue engagement devices, systems, and methods

Abstract

Devices and related methods to engage tissue layers to access the space between the layers are provided. The access devices include engagement arms that can be deployed and retracted to easily engage the top tissue layer and allow it to be separated from the underlying layer. The engagement arms are coupled to an actuation rod that is in turn coupled to a switch or lever that allows a user to control the actuation from outside the patient. The engagement arms and coupling to the actuation rod are unique and compact to ensure the entire mechanism fits in a small diameter shaft.

1 . A tissue engagement device comprising:
 a tube that defines a lumen having a maximum interior width;   an actuation rod positioned within the lumen of the tube;   a plurality of arms, each arm comprising a piercing tip; and   an actuator configured to move the actuation rod relative to the tube to rotate the arms between (i) a retracted orientation in which the tips of adjacent arms are at a distance from each other that is less than the maximum interior width of the lumen and (ii) an actuated orientation in which the tips of adjacent arms are directed away from each other and are spaced from each other by a distance that is greater than the maximum interior width,   wherein, when a distal end of the tissue engagement device abuts a layer of tissue, actuation of the arms via the actuator rotates the tips into the layer of tissue to pierce the layer of tissue and to apply tension to the layer of tissue outwardly in opposite directions, and   wherein the piercing tips of the arms are positioned distally beyond a distal face of the tube when the arms are in the retracted orientation.   
     
     
         2 . The tissue engagement device of  claim 1 , wherein the tips of the arms face away from each other when the tissue engagement device is in the retracted orientation. 
     
     
         3 . The tissue engagement device of  claim 1 , wherein the actuation rod comprises a tip at a distal end thereof, and wherein the piercing tips of the arms extend distally past the distal tip of the actuation rod during at least a portion of a transition of the arms from the retracted orientation to the actuated orientation. 
     
     
         4 . The tissue engagement device of  claim 1 , wherein the piercing tips of the arms extend distally past the distal face of the tube during at least a portion of a transition of the arms from the retracted orientation to the actuated orientation. 
     
     
         5 . The tissue engagement device of  claim 1 , wherein at least a portion of each arm is positioned distally relative to the distal face of the tube throughout a transition of the arms from the retracted orientation to the actuated orientation. 
     
     
         6 . The tissue engagement device of  claim 1 , wherein the arms are pivotally coupled either to the tube or to the actuation rod. 
     
     
         7 . The tissue engagement device of  claim 1 , further comprising a puncture needle that comprises a tip configured to puncture through a tissue layer after the tissue layer has been engaged by the arms. 
     
     
         8 . The tissue engagement device of  claim 7 , wherein the actuation rod defines a needle pathway through which the puncture needle passes. 
     
     
         9 . The tissue engagement device of  claim 8 , wherein the needle pathway is either parallel to or collinear with a central axis of the tube. 
     
     
         10 . The tissue engagement device of  claim 8 , wherein the needle pathway extends between the arms. 
     
     
         11 . The tissue engagement device of  claim 7 , further comprising a fitting attached to the proximal end of the puncture needle, the fitting comprising a Luer connection interface. 
     
     
         12 . The tissue engagement device of  claim 1 , wherein the actuator comprises a lever, a knob, or a sliding button. 
     
     
         13 . The tissue engagement device of  claim 1 , wherein the actuation rod is moved distally relative to the tube to transition the arms from the retracted orientation to the actuated orientation. 
     
     
         14 . The tissue engagement device of  claim 1 , wherein the piercing tips of the arms are configured to embed within or otherwise engage the pericardium of a heart without passing through the pericardium of the heart when the arms are transitioned from the retracted orientation to the actuated orientation. 
     
     
         15 . The tissue engagement device of  claim 1 , wherein the piercing tips of the arms are configured to move only in transverse and proximal directions relative to the tube when the arms are transitioned from the retracted orientation to the actuated orientation. 
     
     
         16 . The tissue engagement device of  claim 1 , wherein the piercing tips of the arms move in unison with each other along oppositely directed paths as the arms are transitioned from the retracted orientation to the actuated orientation. 
     
     
         17 . The tissue engagement device of  claim 1 , wherein the piercing tips of the arms are at the distal end of the tissue engagement device when the arms are in the retracted orientation. 
     
     
         18 . The tissue engagement device of  claim 1 , wherein the actuation rod comprises a tip at the distal end of the tissue engagement device, wherein the tip of the actuation rod is recessed relative to the distal face of the tube when the arms are in the retracted orientation. 
     
     
         19 . The tissue engagement device of  claim 1 , wherein the piercing tips of the arms are each sharpened along one or more bevel planes. 
     
     
         20 . A tissue engagement device comprising:
 a tube that defines a lumen having a maximum interior width;   an actuation rod configured to be positioned within the lumen of the tube, the actuation rod defining a needle pathway;   a plurality of arms, each arm comprising a piercing tip;   an actuator configured to move the actuation rod relative to the tube to transition the arms between (i) a retracted orientation in which the tips of adjacent arms are at a distance from each other that is less than the maximum interior width of the lumen and (ii) an actuated orientation in which the tips of adjacent arms are directed away from each other and are spaced from each other by a distance that is greater than the maximum interior width; and   a needle configured to pass through the needle pathway of the actuation rod while the arms are in the actuated orientation,   wherein, when a distal end of the tissue engagement device abuts a layer of tissue, actuation of the arms via the actuator introduces the tips into the layer of tissue to engage the layer of tissue and to apply tension to the layer of tissue outwardly in opposite directions,   wherein, proximal movement of the tissue engagement device when the arms are in the actuated orientation and engage the layer of tissue causes the layer of tissue to lift away from underlying tissue, and   wherein the needle pathway is oriented to direct a distal end of the needle to puncture through the layer of tissue as the needle is advanced distally through the needle pathway while the layer of tissue remains lifted away from the underlying tissue.   
     
     
         21 . The tissue engagement device of  claim 20 , wherein the needle pathway is collinear with a central axis of the tube. 
     
     
         22 . The tissue engagement device of  claim 20 , wherein the needle pathway extends between the arms when the arms are in the actuated orientation. 
     
     
         23 . A tissue engagement device comprising:
 a tube that defines a lumen having a maximum interior width;   an actuation rod configured to be positioned within the lumen of the tube, the actuation rod defining a needle pathway;   a plurality of arms, each arm comprising a piercing tip;   an actuator configured to move the actuation rod relative to the tube to transition the arms between (i) a retracted orientation in which the tips of adjacent arms are at a distance from each other that is less than the maximum interior width of the lumen and (ii) an actuated orientation in which the tips of adjacent arms are directed away from each other and are spaced from each other by a distance that is greater than the maximum interior width; and   a needle configured to pass through the needle pathway of the actuation rod,   wherein the needle pathway extends between the arms when the arms are in the actuated orientation.   
     
     
         24 . The tissue engagement device of  claim 23 , wherein the needle pathway extends between the arms when the arms are in the retracted orientation.