Microwave ablation instrument with insertion probe

Abstract

A microwave ablation assembly and method including a relatively thin, elongated probe ( 21 ) having a proximal access end ( 22 ) and an opposite distal penetration end ( 23 ) adapted to penetrate into bio-tissue ( 25 ). The probe ( 21 ) defines an insert passage ( 26 ) extending therethrough from the access end ( 22 ) to the penetration end ( 23 ) thereof. An ablation catheter includes a coaxial transmission line ( 28 ) with an antenna device ( 30 ) coupled to a distal end of the transmission line ( 28 ) for generating an electric field sufficiently strong to cause tissue ablation. The coaxial transmission line ( 28 ) includes an inner conductor ( 31 ) and an outer conductor ( 32 ) separated by a dielectric material medium ( 33 ). A proximal end of the transmission line ( 28 ) is coupled to a microwave energy source. The antenna device ( 30 ) and the transmission line ( 28 ) each have a transverse cross-sectional dimension adapted for sliding receipt through the insert passage ( 26 ) while the elongated probe ( 21 ) is positioned in the bio-tissue ( 25 ). Such sliding advancement continues until the antenna device ( 30 ) is moved to a position beyond the penetration end ( 23 ) and further into direct contact with the bio-tissue ( 25 ).

1 - 24 . (canceled)  
     
     
         25 . A method for ablating bio-tissue using an electrically conductive elongated probe having a passage extending therethrough between proximal and distal ends thereof, the method comprising: 
 introducing the probe into targeted bio-tissue to a selected location of the distal end therein;    applying suction to the passage from the proximal end thereof to extract a specimen of bio-tissue at the selected location therein adjacent the distal end of the probe;    introducing into the passage from the proximal end a microwave ablation device having a distal antenna coupled via a transmission line to a source of microwave energy;    slidably positioning the antenna within the passage beyond the distal end of the probe; and    supplying microwave energy via the transmission line to the antenna with sufficient intensity to ablate the bio-tissue adjacent the distal end of the probe.    
     
     
         26 . The method according to  claim 25 , in which the conductive probe forms a portion of the transmission line, and in which the method includes introducing the probe into targeted bio-tissue along a curved path; and 
 the antenna is slidably positioned within the passage along the curved path.    
     
     
         27 . The method according to  claim 25  in which the probe is introduced percutaneously into the targeted bio-tissue.  
     
     
         28 . Tissue ablation apparatus comprising: 
 an elongated conductive probe having a passage therein extending between proximal and distal ends thereof; and    an antenna slidably disposed within the passage to extend beyond the distal end of the probe, and coupled via a transmission line to a source of microwave energy, the conductive probe forming an outer conductive portion of the transmission line about an inner conductor at least near the distal end of the probe, the inner conductor and outer conductor portion being electrically separated by a dielectric therebetween.    
     
     
         29 . Tissue ablation apparatus according to  claim 28 , in which the antenna is a monopole configured with the assembly of inner conductor and dielectric slidably extendable from within the passage beyond the distal end of the probe.  
     
     
         30 . Tissue ablation apparatus as in  claim 28  in which the probe is curved near the distal end thereof; and 
 the assembly of inner conductor and dielectric at least near the distal end of the probe is flexible for slidable extension thereof through the curved passage beyond the distal end.    
     
     
         31 . Tissue ablation apparatus comprising: 
 an elongated probe having a passage therein extending between a proximal end and a distal end that is configured to penetrate targeted bio-tissue;    an antenna slidably disposed within the passage to extend beyond the distal end; and    a transmission line including an inner conductor positioned within an outer conductor separated therefrom by a dielectric, the transmission line being electrically coupled to the antenna and being slidable therewith within the passage for extension of a portion of the outer conductor beyond the distal end of the probe with a distal portion of the inner conductor and dielectric extending distally beyond the outer conductor.