Methods for electrosurgical treatment of spinal tissue

Abstract

Systems, apparatus, and methods for treating spinal tissue and other body structures in open and endoscopic spine surgery to relieve symptoms, such as neck or back pain. In particular, the present invention provides methods for the controlled heating of various tissues in or around the vertebral column, including various interspinous tissues, such that spinal ligaments and cartilage surrounding the vertebrae and the facet joints are shrunk or tightened to stabilize the vertebral column of a patient. Thermal energy is applied to the target tissue in a subablation mode of an electrosurgical system to cause shrinkage of the tissue, thereby stiffening the interspinous tissue and stabilizing the vertebral column. In an exemplary embodiment, a high frequency RF voltage can be applied between one or more active electrode(s) and one or more return electrode(s) to heat a target interspinous tissue to within a temperature range at which irreversible shrinkage of the tissue occurs.

1 - 25 . (canceled)  
   
   
       26 . A method of treating an intervertebral disc comprising: 
 a) positioning an active electrode of an electrosurgical probe adjacent to or within a nucleus pulposus of the intervertebral disc;    b) treating the nucleus pulposus by applying high frequency voltage between the active electrode and a return electrode;    c) withdrawing the active electrode through an annular fibrosus of the intervertebral disc; and    d) during the withdrawing step, applying a high frequency voltage between the active electrode and the return electrode sufficient to contract annulus fibrosus.    
   
   
       27 . The method of  claim 26 , wherein the treating of the nucleus polposus step comprises applying a high frequency voltage between the active electrode and the return electrode sufficient to heat a portion of the nucleus polposus to a temperature between about 55° C. and about 70° C.  
   
   
       28 . The method of  claim 26 , wherein the treating of the nucleus polposus step comprises applying a high frequency voltage between the active electrode and the return electrode sufficient to ablate a portion of the nucleus pulposus.  
   
   
       29 . The method of  claim 26  wherein the active electrode and the return electrode are disposed on the distal end of the probe.  
   
   
       30 . The method of  claim 26  wherein the return electrode is not disposed on the electrosurgical probe.  
   
   
       31 . The method of  claim 26  wherein, during the withdrawing step, applying a high frequency voltage between the active electrode and the return electrode sufficient to contract at least a portion of the annulus fibrosus.  
   
   
       32 . The method of  claim 26  wherein, during the withdrawing step, applying a high frequency voltage between the active electrode and the return electrode sufficient to heat a portion of the annulus fibrosus to a temperature between about 55° C. and about 70° C.  
   
   
       33 . The method of  claim 26  wherein, during the withdrawing step, applying a high frequency voltage between the active electrode and the return electrode sufficient to coagulate blood at the tissue surface of the annulus fibrosus.  
   
   
       34 . The method of  claim 26  wherein, during the withdrawing step, applying a high frequency voltage between the active electrode and the return electrode sufficient to coagulate blood at the tissue surface of the annulus fibrosus.  
   
   
       35 . The method of  claim 26  wherein, during the withdrawing step, applying a high frequency voltage between the active electrode and the return electrode sufficient to contract at least a portion of the annulus fibrosus, said high frequency voltage insufficient to cause ablation of tissue.  
   
   
       36 . The method of  claim 26 , further comprising: 
 providing a quantity of an electrically conductive fluid around said active electrode, wherein said electrically conductive fluid provides a current flow path between the active electrode and the return electrode.    
   
   
       37 . The method of  claim 26 , wherein said step d) causes shrinkage of collagen fibers of said annulus fibrosus.  
   
   
       38 . The method of  claim 26 , wherein the high frequency voltage is applied between the active electrode and the return electrode sufficient to effect molecular dissociation of annulus pulposus tissue.  
   
   
       39 . The method of  claim 26 , further comprising: 
 e) prior to said step a) introducing the electrosurgical probe into an intervertebral disc.    
   
   
       40 . The method of  claim 26 , wherein said step d) comprises controlled heating of the annulus fibrosus tissue to within a specific temperature range and to a defined depth.  
   
   
       41 . The method of  claim 40 , wherein the defined depth is in a range of from about 0.2 mm to 2.5 mm.  
   
   
       42 . The method of  claim 41  wherein the electrosurgical probe creates a passage through the annulus fibrosus and the application of the high frequency voltage during the withdrawing step seals the passage as the probe is withdrawn.  
   
   
       43 . The method of  claim 26 , further comprising: advancing an introducer needle towards said annulus fibrosus and advancing a shaft of the electrosurgical probe through the introducer needle.  
   
   
       44 . The method of  claim 26  wherein the high frequency voltage applied during the treating step is the same as the high frequency voltage applied during the withdrawing step.  
   
   
       45 . The method of  claim 26  wherein the high frequency voltage applied during the treating step comprises a first high frequency voltage and the frequency voltage applied during the withdrawing step comprises a second high frequency voltage.