Anchored rf ablation device for the destruction of tissue masses

Abstract

The inventive ablation element comprises an elongated cannula having a proximal end and a distal end. The cannula defines an internal lumen and a cannula axis. A plurality of conductors contained within the lumen, each having a proximal end proximate the proximal end of the cannula, and a distal end proximate the distal end of the cannula. A plurality of ablation stylets each has a proximal end and a distal end, and each coupled to the distal end of a respective conductor, the conductors together with their respective stylets being mounted for axial movement. A trocar point defined proximate the distal end of the cannula. A deflection surface positioned between the trocar point and the proximal end of the cannula, the deflection surface being configured and positioned to deflect at least some of the stylets laterally with respect to the cannula axis in different directions defining an ablation volume.

What is claimed is: 
     
         1 . An ablation apparatus, comprising:
 an elongated cannula having a proximal end and a distal end, the cannula defining an internal lumen and a cannula axis;   a plurality of ablation stylets each having a proximal end and a distal end, the stylets comprising a deflectable material and having a low profile configuration when straightened within the cannula; and   one or more deflection surfaces positioned along the cannula and configured to deflect at least some of the stylets into a deployed configuration where the stylets are translated longitudinally in a distal direction to extend at an angle relative to the cannula axis such that the stylets are straightened externally of the cannula, wherein the deployed configuration defines an ablation volume.   
     
     
         2 . The apparatus of  claim 1  wherein the plurality of stylets comprise at least one central ablation stylet which is positioned to extend along the cannula axis in the deployed configuration. 
     
     
         3 . The apparatus of  claim 2  further comprising a central conductor contained within the internal lumen, the central conductor extending through the cannula proximal to the distal end of the cannula. 
     
     
         4 . The apparatus of  claim 3  wherein central conductor is coupled with the at least one central ablation stylet. 
     
     
         5 . The apparatus of  claim 1  further comprising a plurality of conductors contained within the internal lumen, wherein each of the conductors is coupled to the respective proximal end of a corresponding stylet and are longitudinally translatable with the corresponding stylet. 
     
     
         6 . The apparatus of  claim 5  wherein the plurality of conductors is selected from the group consisting of electrical conductors, radio frequency conductors, microwave conductors, and optical conductors. 
     
     
         7 . The apparatus of  claim 5  wherein each of the conductors is integral with its respective ablation stylet. 
     
     
         8 . The apparatus of  claim 1  further comprising a trocar point defined proximate the distal end of the cannula. 
     
     
         9 . The apparatus of  claim 1  wherein each of the ablation stylets is configured to assume a straightened configuration in the absence of an external force. 
     
     
         10 . The apparatus of  claim 1  further comprising an actuator configured to longitudinally translate the plurality of ablation stylets. 
     
     
         11 . The apparatus of  claim 1  wherein the one or more deflection surfaces comprise a ramp positioned along the cannula. 
     
     
         12 . The apparatus of  claim 11  wherein the one or more deflection surfaces comprises a plurality of channels guiding the ablation stylets to the one or more ramps. 
     
     
         13 . The apparatus of  claim 1  further comprising an anchor mounted for movement between an internal position and an anchoring position extending laterally from the cannula. 
     
     
         14 . The apparatus of  claim 13  further comprising a drive member disposed within the lumen and coupled to the anchor to drive the anchor between the internal position and the anchoring position. 
     
     
         15 . The apparatus of  claim 13  wherein the anchor comprises at least two pointed members mounted for movement in directions which have vector components which extend away from the axis or the cannula and away from each other. 
     
     
         16 . The apparatus of  claim 13  wherein the at least two pointed members extend in a direction with vector component that extends in a direction opposite to the direction in which cannula extends. 
     
     
         17 . An ablation apparatus, comprising:
 an elongated cannula having a proximal end and a distal end, the cannula defining an internal lumen and a cannula axis;   a plurality of ablation stylets including at least one central ablation stylet which is positioned to extend along the cannula axis, the stylets comprising a deflectable material and having a low profile configuration when straightened within the cannula; and   one or more deflection surfaces positioned along the cannula and configured to deflect at least some of the stylets into a deployed configuration where the stylets are translated longitudinally in a distal direction to extend at an angle relative to the cannula axis such that the stylets are straightened externally of the cannula, wherein the deployed configuration defines an ablation volume.   
     
     
         18 . The apparatus of  claim 17  further comprising a central conductor contained within the internal lumen, the central conductor extending through the cannula proximal to the distal end of the cannula. 
     
     
         19 . The apparatus of  claim 18  wherein central conductor is coupled with the at least one central ablation stylet. 
     
     
         20 . The apparatus of  claim 17  further comprising a plurality of conductors contained within the internal lumen, wherein each of the conductors is coupled to the respective proximal end of a corresponding stylet and are longitudinally translatable with the corresponding stylet. 
     
     
         21 . The apparatus of  claim 17  further comprising a trocar point defined proximate the distal end of the cannula. 
     
     
         22 . The apparatus of  claim 17  further comprising an actuator configured to longitudinally translate the plurality of ablation stylets. 
     
     
         23 . The apparatus of  claim 17  wherein the one or more deflection surfaces comprise a ramp positioned along the cannula. 
     
     
         24 . The apparatus of  claim 23  wherein the one or more deflection surfaces comprises a plurality of channels guiding the ablation stylets to the one or more ramps.