Transurethral systems and methods for ablation treatment of prostate tissue

Abstract

Transurethral systems and methods for delivering electrical energy and controlled, mild heating to a prostate tissue of a patient for destruction of cancerous and/or hyperplastic tissue. A method includes positioning an elongate urethral probe having an expandable member with electrode elements at a target location in the patient's urethra, and inflating or expanding at the target location. Secondary electrodes are positioned within or adjacent to the prostate tissue and spaced from the electrode elements of the expandable member, and an alternating electrical current flow is established between the electrode elements of the expandable member and the one or more secondary electrodes. Current delivery can be selected so as to destroy or ablate cancerous cells of the prostate tissue.

What is claimed is: 
     
         1 . A system for preferential destruction of cancerous or hyperplastic cells of a prostate tissue of a patient, comprising:
 an elongate urethral probe comprising a proximal end and a distal portion having an expandable member, the expandable member comprising one or more conductive electrode elements;   a rectal probe comprising one or more electrode elements disposed on a surface of an expandable member; and   a control system comprising a power source, the control system coupled to the elongate urethral probe and rectal probe and configured to provide electrical current to the electrodes so as to establish a current flow through a volume of the patient's prostate tissue and between the electrode elements of the urethral probe and electrode elements of the rectal probe.   
     
     
         2 . The system of  claim 1 , wherein the system is configured to maintain an average target tissue temperature of less than about 50 degrees C. 
     
     
         3 . The system of  claim 1 , wherein the system is configured to maintain an average target tissue temperature of 45 degrees C. to 49 degrees C. 
     
     
         4 . The system of  claim 1 , wherein the electrical current comprises an alternating electrical current flow comprising a frequency of less than about 300 kHz. 
     
     
         5 . The system of  claim 1 , wherein the alternating electrical current flow comprising a frequency from about 50 kHz to about 300 kHz. 
     
     
         6 . The system of  claim 1 , wherein the alternating electrical current flow comprising a frequency of about 100 kHz. 
     
     
         7 . The system of  claim 1 , wherein system is configured to preferentially destroy cancerous cells of the prostate tissue in the volume relative to non-cancerous cells in the volume. 
     
     
         8 . The system of  claim 1 , wherein the control system is configured to cause delivery of electrical current from at least one of (a) at least one of the one or more conductive electrode elements of the urethral probe, or (b) at least one of the one or more electrode elements of the rectal probe. 
     
     
         9 . The system of  claim 1 , wherein the elongated urethral probe comprises one or more secondary electrodes deployable from a body of the elongated urethral probe. 
     
     
         10 . The system of  claim 9 , wherein the control system is configured to cause an alternating electrical current flow between the deployed one or more secondary electrodes and the electrode elements of the urethral probe. 
     
     
         11 . The system of  claim 10 , wherein the control system is configured to cause delivery of alternating electrical current from at least one of (a) at least one of the one or more conductive electrode elements of the urethral probe, (b) at least one of the one or more electrode elements of the rectal probe, or (c) at least one of one or more current transfer regions of the one or more secondary electrodes disposed within or adjacent to the prostate tissue and spaced from the electrode elements of the elongated urethral probe. 
     
     
         12 . A system for preferential destruction of cancerous or proliferating cells of a target tissue or of a body lumen passing through a target tissue of a patient, comprising:
 an elongate probe comprising a proximal end and a distal portion having an expandable member, the expandable member comprising one or more conductive electrode elements, the distal portion positionable in a body lumen of the patient;   one or more secondary electrodes positionable within or adjacent to the target tissue and spaced from the electrode elements of the expandable member; and   a control system comprising a power source, the control system coupled to the elongate probe and secondary electrode(s) and configured to provide electrical current to the probe and electrode(s) so as to establish a current flow through a volume of the patient's target tissue and between the electrode elements of the probe positioned in the body lumen of the patient and the positioned secondary electrode(s).   
     
     
         13 . The system of  claim 12 , wherein the system is configured to maintain an average target tissue temperature of less than about 50 degrees C. and the electrical current comprises an alternating electrical current flow comprising a frequency of from about 50 kHz to about 300 kHz. 
     
     
         14 . The system of  claim 12 , wherein at least one of the one or more secondary electrodes is deployable from a body of the elongated probe. 
     
     
         15 . The system of  claim 12 , wherein at least one of the one or more secondary electrodes is deployable from the distal portion of the elongated probe. 
     
     
         16 . The system of  claim 12 , wherein the secondary electrodes comprise elongated needle electrodes. 
     
     
         17 . The system of  claim 12 , wherein the control system is configured to cause delivery of alternating electrical current from at least one of (a) at least one of the one or more conductive electrode elements of the elongate probe, or (b) at least one of one or more current transfer regions of the one or more secondary electrodes that is disposed within or adjacent to the target tissue and spaced from the conductive electrode elements of the expandable member. 
     
     
         18 . The system of  claim 12 , further comprising a source for flowing a heated or cooled inflation media through the expandable member during energy delivery. 
     
     
         19 . The system of  claim 12 , further comprising a feedback unit configured to measure electric field delivery parameters and/or characteristics of the target tissue. 
     
     
         20 . The system of  claim 12 , further comprising an imaging device for providing images of tissues during use of the elongate probe.