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 . A method of treating an interspinous tissue of a patient, comprising: 
 a) positioning an active electrode adjacent to a target site of the interspinous tissue, said active electrode is disposed on the distal end of a shaft of an electrosurgical probe; and    b) heating the interspinous tissue at the target site with the active electrode by applying a high frequency voltage between the active electrode and a return electrode, the heating being sufficient to shrink at least a portion of the interspinous tissue.    
     
     
         2 . The method of  claim 1 , wherein the electrosurgical probe is coupled to a high frequency power supply to provide a power supply/probe combination, the power supply/probe combination configured to operate in either an ablation mode wherein a first high frequency voltage is applied between the active electrode and the return electrode sufficient to effect molecular dissociation of the interspinous tissue, or in a subablation mode wherein a second high frequency voltage applied between the active electrode and the return electrode effects thermal heating and shrinkage of the interspinous tissue.  
     
     
         3 . The method of  claim 1  wherein the return electrode is disposed on the shaft distal end at a location proximal to the active electrode such that current is induced to flow from the active electrode away from the interspinous tissue.  
     
     
         4 . The method of  claim 1  wherein the high frequency voltage applied between the active and return electrodes is insufficient to cause ablation of tissue.  
     
     
         5 . The method of  claim 1  further comprising: 
 c) providing a quantity of an electrically conductive fluid around the active electrode, wherein the electrically conductive fluid provides a current flow path between the active electrode and the return electrode.    
     
     
         6 . The method of  claim 5  wherein applying a high frequency voltage between the active electrode and the return electrode heats the quantity of electrically conductive fluid, and the heated electrically conductive fluid heats the interspinous tissue at the target site.  
     
     
         7 . The method of  claim 5  wherein said step c) comprises delivering the electrically conductive fluid to the shaft distal end, and said step c) is performed after the positioning step and prior to the applying step.  
     
     
         8 . The method of  claim 1  wherein said step b) comprises heating the interspinous tissue in a controlled manner such that tissue at the target site is exposed to a temperature in the range of from about 60° to 70° C.  
     
     
         9 . The method of  claim 1  wherein said step b) causes shrinkage of collagen fibers of the interspinous tissue and increased rigidity of the vertebral column of the patient.  
     
     
         10 . The method of  claim 1  wherein the interspinous tissue is a ligament.  
     
     
         11 . The method of  claim 10  wherein the ligament is an anterior longitudinal ligament, a posterior longitudinal ligament, a supraspinous ligament, a ligamentum flavum, or an interspinous ligament.  
     
     
         12 . The method of  claim 1  wherein the interspinous tissue comprises cartilage or a capsule surrounding a facet joint between adjacent vertebrae.  
     
     
         13 . The method of  claim 1  wherein the interspinous tissue is located adjacent to a spinous processes.  
     
     
         14 . The method of  claim 1  wherein said step b) causes adjacent spinous processes to be drawn closer together.  
     
     
         15 . The method of  claim 1  wherein said step b) causes tightening of at least one facet joint between adjacent vertebrae.  
     
     
         16 . The method of  claim 1  wherein said interspinous tissue comprises tissue adjacent a facet joint.