Tissue ablation apparatus with a sliding ablation instrument and method

Abstract

A system and method for ablating a selected portion of a contact surface of biological tissue is provided. The system includes an elongated ablation sheath having a preformed shape adapted to substantially conform a predetermined surface thereof with the contact surface of the tissue. The ablation sheath defines an ablation lumen sized to slideably receive an elongated ablative device longitudinally therethrough. The ablative device includes a flexible ablation element selectively generating an ablative field sufficiently strong to cause tissue ablation. Advancement of the ablation element slideably through the ablation lumen of the ablation sheath selectively places the ablation element along the ablation path for guide ablation on the contact surface when the predetermined surface is in strategic contact therewith. The ablation lumen and the ablative device cooperate to position the ablation element proximate to the ablation sheath predetermined surface for selective ablation of the selected portion within the ablative field.

1 . A guide sheath comprising: 
 a proximal end portion, a distal end portion, and at least one lumen extending between the proximal and distal end portions, said at least one lumen being sized and dimensioned to longitudinally slideably receive an ablative device therethrough, said distal end portion having a preformed shape which is moveable between a substantially linear configuration for insertion into and through an introducer which is adapted to deliver the guide sheath into a selected chamber within a heart of a patient, and an operable configuration wherein said distal end portion has a loop shape configuration which is sized and dimensioned to substantially encircle an opening to a pulmonary vein.    
     
     
         2 . The guide sheath of  claim 1  further including 
 a second section extending from said first section and having a substantially longitudinal configuration.  
 
     
     
         3 . The guide sheath of  claim 2  wherein 
 said distal end portion has a distal end which is closed.  
 
     
     
         4 . The guide sheath of  claim 2  wherein 
 said second section includes at least one electrode.  
 
     
     
         5 . The guide sheath of  claim 1  wherein 
 said guide sheath further includes a lumen used to inject a contrast agent.  
 
     
     
         6 . The guide sheath of  claim 1  wherein 
 said loop shape configuration section includes at least one electrode.  
 
     
     
         7 . The guide sheath of  claim 2  wherein 
 said second section is configured to extend a short distance within the opening to the pulmonary vein when said first section is located at or near the tissue region extending about the periphery of the opening to the pulmonary vein.  
 
     
     
         8 . The guide sheath of  claim 7  wherein 
 said electrode is configured to monitor electrical signals within the pulmonary vein.  
 
     
     
         9 . A guide sheath comprising 
 a proximal end portion, a distal end portion, and at least one lumen, the distal end portion having a pre-shaped configuration including at least first and second sections, said first section having a loop configuration sized and dimensioned to substantially encircle an opening to a pulmonary, said second section extending from said first section and having a substantially linear configuration, said second section including at least one electrode.    
     
     
         10 . A guide sheath comprising 
 a proximal end portion, a distal end portion, and at least one lumen extending between the proximal and distal end portions, said at least one lumen being sized and dimensioned to longitudinally slideably receive an ablative device therethrough, said distal end portion having a preformed shape which is moveable between a substantially linear configuration for insertion into and through an introducer which is adapted to deliver the guide sheath into a selected chamber within a heart of a patient, and an operable configuration wherein said distal end portion has a curvilinear shape configuration which is sized and dimensioned to substantially follow the wall of a interior cardiac chamber.    
     
     
         11 . The guide sheath of  claim 10  wherein 
 said interior cardiac chamber is selected from a right or a left atrium.  
 
     
     
         12 . The guide sheath of  claim 10  wherein 
 said interior cardiac chamber is selected from a right or a left ventricle.  
 
     
     
         13 . The guide sheath of  claim 10  wherein 
 said distal end portion includes at least one electrode.  
 
     
     
         14 . The guide sheath of  claim 10  wherein 
 said curvilinear shape is configured to substantially follow the posterior wall of the left atrium between two pulmonary veins.  
 
     
     
         15 . The guide sheath of  claim 10  wherein 
 said curvilinear shape is configured to substantially follow the posterior wall of the left atrium between a pulmonary vein and the mitral valve.  
 
     
     
         16 . The guide sheath of  claim 10  wherein 
 said curvilinear shape is configured to substantially follow the posterior wall of the left atrium between a pulmonary vein and the left atrial appendage.  
 
     
     
         17 . The guide sheath of  claim 10  wherein 
 said curvilinear shape is configured to substantially follow the isthmus between the inferior caval vein and the tricuspid valve.  
 
     
     
         18 . The guide sheath of  claim 10  wherein 
 said curvilinear shape is configured to substantially follow the lateral right free wall between the superior and inferior caval veins.