Ablation apparatus and system to limit nerve conduction

Abstract

An electrosurgical probe including a probe body which defines a longitudinal probe axis. The electrosurgical probe also includes a first and second conductive electrode, each disposed along the probe axis. The surface area of the first conductive electrode is greater of the surface area of the second conductive electrode. The ratio of the surface area of the first conductive electrode to the surface area of the second conductive electrode may be adjustable. Another aspect of the present invention is an electrosurgical probe having a probe body which defines a single longitudinal probe axis. The electrosurgical probe of this aspect of the invention further includes more than two electrodes operatively disposed at separate and distinct positions along the axis of the probe body. The electrodes may be selectively connected to one of or a combination of a stimulation energy source, an ablation energy source or a ground for either energy source. Another aspect of the present invention is a method of placing an electrosurgical probe such as described above for specific ablation procedures.

1 . An electrosurgical probe comprising: 
 a probe body defining a longitudinal probe axis; and    a first and a second conductive electrode operatively disposed along the probe axis wherein the surface area of the first conductive electrode is substantially greater than the surface area of the second conductive electrode.    
     
     
         2 . The electrosurgical probe of  claim 1  wherein a ratio of the surface area of the first conductive electrode to the surface area of the second conductive electrode is equal to or greater than 3:1.  
     
     
         3 . The electrosurgical probe of  claim 1  wherein a ratio of the surface area of the first conductive electrode to the surface area of the second conductive electrode is equal to or greater than 8:1.  
     
     
         4 . The electrosurgical probe of  claim 1 , wherein a ratio of the surface area of the first conductive electrode to the surface area of the second conductive electrode is adjustable.  
     
     
         5 . The electrosurgical probe of  claim 1  further comprising a stimulation energy source in electrical communication with at least one of the first or second conductive electrodes.  
     
     
         6 . The electrosurgical probe of  claim 5  further comprising an ablation energy source in electrical communication with at least one of the first or second conductive electrodes.  
     
     
         7 . The electrosurgical probe of  claim 6  further comprising a switch providing for the selective connection of the stimulation energy source or the ablation energy source to at least one of the conductive electrodes.  
     
     
         8 . An electrosurgical probe comprising: 
 a probe body defining a longitudinal probe axis;    an active electrode operatively associated with the probe body at a first location along the probe axis;    a stimulation electrode operatively associated with the probe body at a second location along the probe axis; and    a return electrode operatively associated with the probe body at a third location along the probe axis.    
     
     
         9 . The electrosurgical probe of  claim 8  wherein the stimulation electrode is positioned along the probe axis between the active electrode and the return electrode.  
     
     
         10 . The electrosurgical probe of  claim 8  further comprising a stimulation energy source in electrical communication with the stimulation electrode.  
     
     
         11 . The electrosurgical probe of  claim 10  wherein the stimulation energy source provides variable stimulation current.  
     
     
         12 . The electrosurgical probe of  claim 10  wherein at least one of the active electrode and the return electrode is in electrical communication with a ground for the stimulation energy source.  
     
     
         13 . The electrosurgical probe of  claim 10  wherein both of the active electrode and the return electrode are in electrical communication with a ground for the stimulation energy source.  
     
     
         14 . The electrosurgical probe of  claim 7  further comprising an ablation energy source in electrical communication with the active electrode.  
     
     
         15 . The electrosurgical probe of  claim 13  wherein the ablation energy source provides variable ablation energy.  
     
     
         16 . The electrosurgical probe of  claim 15  wherein the ablation energy source provides energy which has at least one of variable voltage, current and waveform.  
     
     
         17 . An electrosurgical probe comprising: 
 a probe body defining a longitudinal probe axis;    at least three electrodes operatively associated with the probe body at separate locations along the probe axis; and    a stimulation energy source in electrical communication with at least one of the electrodes.    
     
     
         18 . The electrosurgical probe of  claim 17  wherein the stimulation energy source provides variable stimulation energy.  
     
     
         19 . The electrosurgical probe of  claim 17  wherein the stimulation energy source may be selectively connected to at least one or more of the electrodes.  
     
     
         20 . The electrosurgical probe of  claim 17  further comprising a stimulation energy ground in electrical communication with the stimulation energy source, wherein the stimulation energy ground may be selectively connected to at least one or more of the electrodes.  
     
     
         21 . The electrosurgical probe of  claim 17  further comprising an ablation energy source in electrical communication with at least one of the electrodes.  
     
     
         22 . The electrosurgical probe of  claim 21  wherein the ablation energy source provides variable ablation energy.  
     
     
         23 . The electrosurgical probe of  claim 22  wherein the ablation energy source provides energy which has at least one of variable voltage, current and waveform.  
     
     
         24 . The electrosurgical probe of  claim 21  wherein the ablation current source may be selectively connected to at least one or more of the electrodes.  
     
     
         25 . The electrosurgical probe of  claim 21  further comprising an ablation energy ground for the ablation energy source, wherein the ablation energy ground may be selectively connected to one or more of the electrodes.  
     
     
         26 . A method of positioning an electrosurgical probe comprising: 
 providing an electrosurgical probe having a probe body defining a longitudinal probe axis, multiple conductive electrodes operatively disposed along the probe axis, and a stimulation energy source in electrical communication with at least one of the conductive electrodes;    inserting the electrosurgical probe to a first position within tissue containing a target nerve;    applying first stimulation energy to the stimulation electrode;    observing a first response of a muscle associated with the target nerve;    moving the electrosurgical probe to a second position within the tissue containing the target nerve;    applying second stimulation energy to the stimulation electrode; observing a second response of a muscle associated with the target nerve; and    comparing the second response of the muscle associated with the target nerve to the first response of the muscle associated with the target nerve.    
     
     
         27 . The method of  claim 26  further comprising: 
 providing a variable stimulation energy source; and    varying the stimulation energy between the first and the second applications of stimulation energy.    
     
     
         28 . A method of positioning an electrosurgical probe comprising: 
 providing an electrosurgical probe having a probe body defining a longitudinal probe axis, multiple conductive electrodes operatively disposed along the probe axis, and a stimulation energy source which may be connected sequentially to more than one of the conductive electrodes;    inserting the electrosurgical probe into tissue containing a target nerve;    applying stimulation current to a select first electrode;    observing a first response of a muscle associated with the target nerve; applying stimulation energy to a select second electrode;    observing a second response of the muscle associated with the target nerve; and    comparing the second response of the muscle associated with the target nerve to the first response of the muscle associated with the target nerve.    
     
     
         29 . The method of  claim 28  further comprising: 
 applying stimulation energy to a select third electrode; observing a third response of the muscle associated with the target nerve; and    comparing the third response of the muscle associated with the target nerve to the second response of the muscle associated with the target nerve.    
     
     
         30 . The method of  claim 29  further comprising sequentially applying stimulation energy to the first, second and third electrodes.