Enhanced needle array and therapies for tumor ablation

Abstract

Novel and versatile apparatuses for delivering one or more of thermal ablation and irreversible electroporation therapies to target tissue. In some examples, a device includes at its distal end a plurality of electrodes that can be advanced or retracted to pierce patient tissue, with a variable position and size shaft electrode provided near the distal end of the device to allow manipulation of therapy fields to achieve various tissue destruction field shapes. A number of method of use examples are described as well.

The claimed invention is: 
     
         1 . A system for destruction of tissue comprising:
 a cannula having a proximal end and a distal end and containing a plurality of tissue penetrating elongate electrodes therein, the electrodes being extendible beyond the distal end of the cannula;   an inner shaft formed from a dielectric polymer disposed over the cannula and carrying a shaft electrode formed from a conductive metal, the shaft electrode disposed near the distal end of the cannula at a spacing distance from the distal end of the cannula, wherein the inner shaft is moveable relative to the cannula to adjust the spacing distance;   electrical connectors including at least one electrical connector electrically coupled to at least one of the elongate electrodes, and at least one electrical connector electrically coupled to the shaft electrode; and   a sheath movable relative to the shaft electrode and inner shaft and adapted to control exposure of the shaft electrode to patient tissue.   
     
     
         2 . The system of  claim 1  wherein the cannula includes a fluid delivery lumen and a distal portion of the cannula comprises one or more apertures for fluid infusion, further wherein the one or more apertures for fluid infusion are located on a first side of the cannula, and the shaft electrode is located on a second side of the cannula, such that the apertures and shaft electrode occupy opposing sides of the cannula within a single axial region of the cannula. 
     
     
         3 . The system of  claim 1  wherein at least one of the tissue penetrating elongate electrodes comprises a dielectric coating on a first side of a portion thereof. 
     
     
         4 . The system of  claim 1  wherein the plurality of tissue penetrating electrodes includes at least a first tissue penetrating electrode having a first electrical connection and a second tissue penetrating electrode having a second electrical connection, wherein the first and second electrical connections are separately addressable. 
     
     
         5 . The system of  claim 4  wherein the sheath is adapted to cover a radial portion of the shaft electrode to facilitate directional control of an output electrical field between a selected one or more of the first and second tissue penetrating electrodes and a portion of the shaft electrode. 
     
     
         6 . The system of  claim 1  wherein the plurality of tissue penetrating electrodes includes at least a first tissue penetrating electrode having a first mechanical coupling and a second tissue penetrating electrode having a second mechanical coupling, wherein the first and second mechanical couplings are separately actuatable to allow the first and second tissue penetrating electrodes to be advanced independent of one another. 
     
     
         7 . The system of  claim 1  wherein the shaft electrode is cylindrical and extends around the inner shaft. 
     
     
         8 . The system of  claim 1  wherein the sheath covers the inner shaft. 
     
     
         9 . The system of  claim 1  wherein the shaft electrode has a proximal end on the inner shaft and a distal end on the inner shaft, and the sheath covers the inner shaft and sheath. 
     
     
         10 . A system for destruction of tissue comprising:
 a cannula having a proximal end and a distal end and containing a plurality of tissue penetrating elongate electrodes therein, the electrodes being extendible beyond the distal end of the cannula;   an inner shaft formed from a dielectric polymer disposed over the cannula and carrying a shaft electrode formed from a conductive metal, the shaft electrode disposed near the distal end of the cannula, the inner shaft being moveable relative to the cannula to enable a distance from the shaft electrode to the distal end of the cannula to be adjustable; and   a plurality of electrical connectors including at least one electrical connector electrically coupled to at least one of the elongate electrodes, and at least one electrical connector electrically coupled to the shaft electrode;   wherein the shaft electrode is disposed at a spacing distance from the distal end of the cannula, wherein the spacing distance is adjustable.   
     
     
         11 . The system of  claim 10  wherein the plurality of tissue penetrating elongate electrodes includes at least a first tissue penetrating electrode having a first mechanical coupling and a second tissue penetrating electrode having a second mechanical coupling, wherein the first and second mechanical couplings are separately actuatable to allow the first and second tissue penetrating electrodes to be advanced independent of one another. 
     
     
         12 . The system of  claim 10  wherein the cannula includes a fluid delivery lumen and a distal portion of the cannula comprises one or more apertures for fluid infusion, further wherein the one or more apertures for fluid infusion are located on a first side of the cannula, and the shaft electrode is located on a second side of the cannula, such that the apertures and shaft electrode occupy opposing sides of the cannula within a single axial region of the cannula. 
     
     
         13 . The system of  claim 10  wherein at least one of the tissue penetrating elongate electrodes comprises a dielectric coating on a first side of a portion thereof. 
     
     
         14 . The system of  claim 10  wherein the plurality of tissue penetrating electrodes includes at least a first tissue penetrating electrode having a first electrical connection and a second tissue penetrating electrode having a second electrical connection, wherein the first and second electrical connections are separately addressable. 
     
     
         15 . The system of  claim 14  wherein the sheath is adapted to cover a radial portion of the shaft electrode to facilitate directional control of an output electrical field between a selected one or more of the first and second tissue penetrating electrodes and a portion of the shaft electrode. 
     
     
         16 . The system of  claim 10  wherein the plurality of tissue penetrating electrodes includes at least a first tissue penetrating electrode having a first mechanical coupling and a second tissue penetrating electrode having a second mechanical coupling, wherein the first and second mechanical couplings are separately actuatable to allow the first and second tissue penetrating electrodes to be advanced independent of one another. 
     
     
         17 . The system of  claim 10  wherein the shaft electrode is cylindrical and extends around the inner shaft. 
     
     
         18 . The system of  claim 10  wherein the sheath covers the inner shaft. 
     
     
         19 . The system of  claim 10  wherein the shaft electrode has a proximal end on the inner shaft and a distal end on the inner shaft, and the sheath covers the inner shaft and sheath. 
     
     
         20 . A system for destruction of tissue comprising:
 a cannula having a proximal end and a distal end and containing a plurality of tissue penetrating elongate electrodes therein, the electrodes being extendible beyond the distal end of the cannula;   moveable electrode means disposed over the cannula, the moveable electrode means being moveable relative to the cannula to enable a distance from the moveable electrode means to the distal end of the cannula to be adjustable;   a plurality of electrical connectors including at least one electrical connector electrically coupled to at least one of the elongate electrodes, and at least one electrical connector electrically coupled to the shaft electrode;   cover means for adjustably covering all, a portion of, or none of the moveable electrode means.