System and method of treating abnormal tissue in the human esophagus

Abstract

An ablation catheter system and method of use is provided to endoscopically access portions of the human esophagus experiencing undesired growth of columnar epithelium. The ablation catheter system and method includes controlled depth of ablation features and use of either radio frequency spectrum, non-ionizing ultraviolet radiation, warm fluid or microwave radiation, which may also be accompanied by improved sensitizer agents.

1 . (canceled) 
     
     
         2 . A method of ablating abnormal esophageal tissue within a target area in an esophagus comprising:
 identifying abnormal esophageal tissue within the target area;   advancing an ablation device into contact with the target area;   selecting settings on the ablation device for delivering energy to the abnormal esophageal tissue within the target area;   delivering energy to a surface of the abnormal esophageal tissue in the target area based on the selected settings; and   changing the settings on the ablation device for delivering energy to the abnormal esophageal tissue within the target area.   
     
     
         3 . The method of  claim 2 , wherein the abnormal esophageal tissue is cancerous tissue. 
     
     
         4 . The method  claim 2 , wherein the abnormal esophageal tissue is squamous intra-epithelial neoplasia. 
     
     
         5 . The method of  claim 2 , wherein delivering energy to the surface of the abnormal esophageal tissue in the target area comprises delivering energy nearly circumferentially about the esophagus. 
     
     
         6 . The method of  claim 2 , wherein delivering energy to the surface of the abnormal esophageal tissue in the target area comprises delivering energy less than circumferentially about the esophagus. 
     
     
         7 . The method of  claim 2 , wherein changing the settings on the ablation device for delivering energy to the abnormal esophageal tissue within the target area comprises changing the settings such that sufficient energy is delivered to achieve ablation in one portion of the surface of the abnormal esophageal tissue and insufficient energy is delivered to achieve ablation in another portion of the surface of the abnormal esophageal tissue. 
     
     
         8 . The method of  claim 2 , wherein changing the settings on the ablation device for delivering energy to the abnormal esophageal tissue comprises changing the settings such that sufficient energy to achieve ablation is delivered to the abnormal esophageal tissue within the target area and insufficient energy to achieve ablation is delivered to other tissue layers beneath the abnormal esophageal tissue within the target area. 
     
     
         9 . The method of  claim 2 , wherein changing the settings on the ablation device for delivering energy to the abnormal esophageal tissue comprises changing the settings such that some fraction of abnormal esophageal tissue volume is ablated and another fraction of abnormal esophageal tissue volume is not ablated. 
     
     
         10 . The method of  claim 7 , wherein changing the settings on the ablation device for delivering energy to the abnormal esophageal tissue consists of changing the settings such that a fraction of tissue in the epithelial layer of the abnormal esophageal tissue within the target area is ablated. 
     
     
         11 . The method of  claim 7 , wherein changing the settings on the ablation device for delivering energy to the abnormal esophageal tissue consists of changing the settings such that a fraction of tissue in the epithelial layer and the lamina propria of the abnormal esophageal tissue within the target area is ablated. 
     
     
         12 . The method of  claim 7 , wherein changing the settings on the ablation device for delivering energy to the abnormal esophageal tissue consists of changing the settings such that a fraction of tissue in the epithelial layer, the lamina propria, and the muscularis mucosae of the abnormal esophageal tissue within the target area is ablated. 
     
     
         13 . The method of  claim 7 , wherein changing the settings on the ablation device for delivering energy to the abnormal esophageal tissue consists of changing the settings such that a fraction of tissue in the epithelial layer, the lamina propria, the muscularis mucosae, and the submucosa of the abnormal esophageal tissue within the target area is ablated. 
     
     
         14 . The method of  claim 2 , wherein delivering energy to a surface of the abnormal esophageal tissue in the target area based on the selected settings comprises delivering energy in a pattern configured to conform to the abnormal esophageal tissue within the target area. 
     
     
         15 . The method of  claim 2 , further comprising evaluating the target area after delivering energy to the surface of the abnormal esophageal tissue in the target area. 
     
     
         16 . The method of  claim 2 , wherein changing the settings on the ablation device for delivering energy to the abnormal esophageal tissue within the target area comprises changing the power settings on the ablation device. 
     
     
         17 . The method of  claim 2 , advancing the ablation device into contact with the target area comprises expanding an expandable member of the ablation device to enhance the contact with the target tissue. 
     
     
         18 . An ablation device for ablating abnormal esophageal tissue within a target area in an esophagus comprising:
 a flexible shaft having a distal end;   a radiant energy distributor located at the distal end of the flexible shaft; and   an ablation control mechanism for controlling the level of radiant energy supplied by the radiant energy distributor.   
     
     
         19 . The ablation device of  claim 18 , further comprising
 an expandable member located proximate the distal end of the flexible shaft.   
     
     
         20 . The ablation device of  claim 18 , wherein the radiant energy distributor comprises an expandable member constructed from electrocondutive elastomeric material. 
     
     
         21 . The ablation device of  claim 18 , wherein the radiant energy distributor comprises an expandable member having an electrode pattern etched onto the exterior surface of the expandable member.