Ablation tools and positioning devices therefor

Abstract

The present invention provides positioning mechanisms for devices that cause conduction blocks or ablation in desired areas of tissue. The positioning mechanisms allow for variable geometry of the target sites and enable more accurate therapy at the tissue site.

1 . A positioning device for an ablation tool comprising: 
 an elongated flexible tube having a distal end and a proximal end;    a sheath removably surrounding at least a portion of said elongated flexible tube; and,    an anchoring device disposed at said distal end of said elongated flexible tube;    an ablation device associated with said elongated flexible tube, said ablation device disposed inside said sheath;    said ablation device predisposed to extend radially away from said elongated flexible tube when said sheath is moved to expose said elongated flexible tube.    
   
   
       2 . A positioning device according to  claim 1 , wherein said anchoring device is a mesh ball.  
   
   
       3 . A positioning device according to  claim 1 , wherein radial extension of said ablation device away from said flexible tube extends to about 4 cm.  
   
   
       4 . A positioning device according to  claim 1 , wherein a distance of said radial extension of said ablation device increases according to movement of said sheath to increase exposure of said elongated flexible tube.  
   
   
       5 . A positioning device according to  claim 1 , wherein an ablation mechanism of said ablation device is selected from the group consisting of: RF energy, laser energy, cryogenic energy, mechanical injury, ultrasonic energy and chemical reactive.  
   
   
       6 . A positioning device according to  claim 1 , wherein said ablation device is comprised of at least one radially extendible arm having a distal ablation tip.  
   
   
       7 . A positioning device according to  claim 1 , wherein said ablation device is comprised of multiple radially extendible arms that generally surround said flexible tube.  
   
   
       8 . A positioning device according to  claim 7 , wherein said multiple radially extendible arms generally form a circle when said elongated flexible tube is sufficiently exposed from said sheath.  
   
   
       9 . A positioning device according to  claim 1  wherein said elongated flexible tube includes a guide wire lumen.  
   
   
       10 . A positioning device according to  claim 1 , wherein said ablation device is rotationally movable around said elongated flexible tube.  
   
   
       11 . A method of ablating tissue around an ostia comprising: 
 providing a catheter containing an ablation device;    anchoring said catheter in an ostial opening of a pulmonary vein;    exposing said ablation device from said catheter;    manipulating said ablation device so as to cause ablation around said ostial opening.    
   
   
       12 . A method according to  claim 11 , wherein anchoring said catheter includes expanding an anchoring device in said ostial opening.  
   
   
       13 . A method according to  claim 12 , wherein expanding an anchoring device includes expanding a mesh ball that substantially conforms to a shape of said ostial opening.  
   
   
       14 . A method according to  claim 11 , wherein exposing said ablation device includes radially extending said ablation device away from said catheter at the same time of the exposing of said ablation device.  
   
   
       15 . A method according to  claim 11 , wherein manipulating said ablation device to cause ablation includes applying at least one of the following items to tissue around said ostial opening: RF energy, laser energy, ultrasonic energy, mechanical injury and chemical reaction.  
   
   
       16 . A method according to  claim 11 , wherein manipulating said ablation device includes indexing said ablation device around said ostial opening and ablating tissue at each index.  
   
   
       17 . A method according to  claim 14 , wherein said radially extending of said ablation device includes increasing the radial extension according to increased exposure of said ablation device from said catheter.  
   
   
       18 . A method according to  claim 17 , further comprising: 
 causing ablation of tissue during the increasing radial extension of said ablation device so as to form a linear ablation in tissue extending from said ostial opening.    
   
   
       19 . A device for ablating tissue around an ostial opening comprising: 
 a catheter assembly having a sheath, a lumen, an anchoring member and an ablation device;    said anchoring member disposed at a distal end of said lumen    said ablation device disposed on said lumen;    said sheath being movable along said lumen such that proximal movement of said sheath relative to said lumen will expose said anchoring member and said ablation device.    
   
   
       20 . A device according to  claim 19 , wherein said ablation device is biased to extend radially outwardly from said lumen when exposed by said sheath.  
   
   
       21 . A device according to  claim 19 , wherein said ablation device is comprised of at least one ablation arm radially extendible from said lumen when exposed by said sheath.  
   
   
       22 . A device according to  claim 19 , wherein said ablation device is rotatable around said lumen when said ablation device is exposed by said sheath.  
   
   
       23 . A device according to  claim 19 , wherein said ablation device includes at least one arm having a distal ablation tip, said distal ablation tip having at least one of the following ablation mechanisms: RF energy, ultrasonic energy, laser energy, mechanical tissue injury, chemical reactive.  
   
   
       24 . A device according to  claim 19 , wherein said anchoring member is an expandable element conformable to said ostial opening.  
   
   
       25 . A device according to  claim 24 , wherein said expandable element is a mesh ball.