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 system for ablating tissue within a body of a patient comprising: 
 an elongated flexible tubular member having at least one lumen and including a pre-shaped distal end portion which is shaped to be positioned adjacent to or in contact with a selected tissue region within the body of the patient; and    an ablative device which is configured to be slideably received longitudinally within said at least one lumen and having an energy delivery portion located near a distal end portion of said ablative device which is adapted to be coupled to an ablative energy source.    
     
     
         2 . The system of  claim 1  wherein 
 said energy delivery portion and ablative energy source are working together to produce the ablation of said selected tissue region.  
 
     
     
         3 . The system of  claim 108  wherein 
 said flexible tubular member includes at least one radio-opaque element.  
 
     
     
         4 . The system of  claim 110  wherein 
 said radio-opaque element can be used to assess the shape of the flexible tubular member during a fluoroscopic procedure.  
 
     
     
         5 . The system of  claim 1  wherein 
 said energy delivery portion includes at least one radio-opaque element.  
 
     
     
         6 . The system of  claim 5  wherein 
 said radio-opaque element is strategically located to identify the extremities of said energy delivery portion.  
 
     
     
         7 . The system of  claim 5  wherein 
 said radio-opaque element is strategically located to identify the ablation location.  
 
     
     
         8 . The system of  claim 1  further including 
 an introducer which is configured to longitudinally receive said flexible tubular member.  
 
     
     
         9 . The system of  claim 8  wherein 
 said introducer has a pre-shaped distal end portion which is configured to be manipulated to direct the flexible tubular member towards the selected tissue region to be ablated following insertion of the distal end portion of the introducer into an interior chamber of the heart.  
 
     
     
         10 . The system of  claim 1  wherein 
 said distal end portion of the flexible tubular member has a distal end which is closed.  
 
     
     
         11 . The system of  claim 1  wherein said energy delivery portion is flexible.  
     
     
         12 . The system of  claim 1  wherein said energy delivery portion is unidirectional.  
     
     
         13 . The system of  claim 1  wherein 
 said energy delivery portion comprises a microwave ablation element.  
 
     
     
         14 . The system of  claim 13  wherein 
 said microwave ablation element is flexible.  
 
     
     
         15 . The system of  claim 13  wherein 
 said microwave ablation element is directional  
 
     
     
         16 . The system of  claim 1  wherein 
 said ablative device is a laser ablation element.  
 
     
     
         17 . The system of  claim 16  wherein 
 said laser ablation element is flexible.  
 
     
     
         18 . The system of  claim 16  wherein 
 said laser ablation element is directional.  
 
     
     
         19 . The system of  claim 1  wherein 
 said energy delivery portion comprises a radiofrequency ablation element.  
 
     
     
         20 . The system of  claim 19  wherein 
 said radiofrequency ablation element is flexible.  
 
     
     
         21 . The system of  claim 19  wherein 
 said radiofrequency ablation element is directional.  
 
     
     
         22 . The system of  claim 1  wherein 
 said energy delivery portion comprises an ultrasound ablation element.  
 
     
     
         23 . The system of  claim 22  wherein 
 said ultrasound ablation element is flexible.  
 
     
     
         24 . The system of  claim 22  wherein 
 said ultrasound ablation element is directional.  
 
     
     
         25 . The system of  claim 1  wherein 
 said energy delivery portion comprises an cryoablation element.  
 
     
     
         26 . The system of  claim 25  wherein 
 said cryoablation element is flexible.  
 
     
     
         27 . The system of  claim 25  wherein 
 said cryoablation element is directional.  
 
     
     
         28 . The system of  claim 1  wherein 
 said energy delivery portion comprises an fluid delivery element.  
 
     
     
         29 . The system of  claim 28  wherein 
 said fluid delivery element is flexible.  
 
     
     
         30 . The system of  claim 28  wherein 
 said fluid delivery element is directional.  
 
     
     
         31 . The system of  claim 1  wherein 
 said distal end portion of the flexible tubular member includes at least first and second sections, said first section having a loop configuration sized and dimensioned to substantially encircle an opening to a pulmonary vein, said second section extending from said first section and having a substantially longitudinal configuration.  
 
     
     
         32 . The system of  claim 31  wherein 
 said second section includes at least one electrode.  
 
     
     
         33 . The system of  claim 1  wherein 
 said distal end portion of the flexible tubular member is shaped to substantially encircle two or more pulmonary veins on an epicardial surface of the heart of the patient.  
 
     
     
         34 . The system of  claim 1  wherein 
 said ablative device comprises a microwave ablation element.  
 
     
     
         35 . The system of  claim 1  wherein 
 said flexible tubular member is sized and dimensioned to be transluminally positioned in an atrial chamber of the heart from a peripheral access vessel.  
 
     
     
         36 . The system of  claim 35  wherein 
 said peripheral access vessel is a femoral artery in a leg of the patient.  
 
     
     
         37 . The system of  claim 35  wherein 
 said peripheral access vessel is a femoral vein in a leg of the patient.  
 
     
     
         38 . The system of  claim 35  wherein 
 said peripheral access vessel is a radial artery or vein in an arm of the patient.  
 
     
     
         39 . The system of  claim 35  wherein 
 said peripheral access vessel is a jugular artery or vein in a neck region of the patient.  
 
     
     
         40 . The system of  claim 1  wherein 
 said flexible tubular member further comprises at least one electrode.  
 
     
     
         41 . The system of  claim 1  wherein 
 said ablative device comprises at least one electrode.  
 
     
     
         42 . The system of  claim 1  wherein 
 said distal end portion of the flexible tubular member includes at least one temperature sensor for measuring a temperature of the tissue region during ablation thereof.  
 
     
     
         43 . The system of  claim 1  wherein 
 said ablative device includes at least one temperature sensor which is adapted to measure a temperature from within the flexible tubular member at one or more locations along a length of the tubular member.  
 
     
     
         44 . The system of  claim 1  wherein 
 said distal end portion of the flexible tubular member includes at least first and second sections, said first section having a loop configuration sized and dimensioned to substantially encircle an opening to a pulmonary vein, said second section extending distally from said first section and having a substantially longitudinal configuration.  
 
     
     
         45 . The system of  claim 44  wherein 
 said second section includes at least one electrode  
 
     
     
         46 . The system of  claim 1  wherein 
 said flexible tubular member includes a key assembly to properly align the energy delivery portion within the distal end portion of the flexible tubular member such that the predetermined direction of the ablative energy aligns with the tissue region to be ablated.  
 
     
     
         47 . The system of  claim 34  wherein 
 said microwave ablation element comprises a microwave antenna which is located within an antenna assembly of the instrument for generating an electromagnetic field sufficient to cause ablation of said tissue region, said antenna assembly being adapted to direct the majority of the electromagnetic field generally in a predetermined direction across the distal end portion of the flexible tubular member.  
 
     
     
         48 . The system of  claim 47  wherein 
 said antenna is configured to generate said electromagnetic field substantially radially from a longitudinal axis of the antenna, and said antenna assembly includes an elongated shield extending partially around and generally in the direction of the longitudinal axis of the antenna, said shield defining an opening adapted to direct said majority of the electromagnetic field generally in said predetermined direction.  
 
     
     
         49 . The system of  claim 47  wherein 
 said flexible tubular member includes a key assembly to properly align the antenna assembly within the distal end portion of the flexible tubular member such that the predetermined direction of the electromagnetic field aligns with the tissue region to be ablated.  
 
     
     
         50 . The system of  claim 16  wherein 
 said laser ablation element comprises a laser emitting element which is located within a laser emitting assembly of the instrument for generating an electromagnetic field sufficient to cause ablation of said tissue region, said laser emitting assembly being adapted to direct the majority of the electromagnetic field generally in a predetermined direction across the distal end portion of the flexible tubular member.  
 
     
     
         51 . The system of  claim 50 , wherein 
 said laser emitting element is configured to generate said electromagnetic field substantially radially from a longitudinal axis of the laser emitting element, and said laser emitting assembly includes an elongated reflector extending partially around and generally in the direction of the longitudinal axis of the laser emitting element, said shield defining an opening adapted to direct said majority of the electromagnetic field generally in said predetermined direction.    
     
     
         52 . The system of  claim 50  wherein 
 said flexible tubular member includes a key assembly to properly align the laser emitting assembly within the distal end portion of the flexible tubular member such that the predetermined direction of the electromagnetic field aligns with the tissue region to be ablated.  
 
     
     
         53 . The system of  claim 25  wherein 
 said ultrasound ablation element comprises at least one ultrasound transducer which is located within an ultrasound ablation assembly of the instrument for generating an acoustic pressure wave sufficient to cause ablation of said tissue region, said ultrasound ablation assembly being adapted to direct the majority of the acoustic pressure wave generally in a predetermined direction across the distal end portion of the flexible tubular member.  
 
     
     
         54 . The system of  claim 53 , wherein 
 said ultrasound transducer is configured to generate said acoustic pressure wave substantially radially from a longitudinal axis of the ultrasound ablation element, and said ultrasound ablation assembly includes an good echogenic material extending partially around and generally in the direction of the longitudinal axis of the ultrasound transducer, said echogenic material defining an opening adapted to direct said majority of the acoustic pressure wave generally in said predetermined direction.    
     
     
         55 . The system of  claim 53  wherein 
 said flexible tubular member includes a key assembly to properly align the ultrasound ablation assembly within the distal end portion of the flexible tubular member such that the predetermined direction of the acoustic pressure wave aligns with the tissue region to be ablated.  
 
     
     
         56 . The system of  claim 25  wherein 
 said cryoablation element comprises a decompression chamber which is located within a cryoablation assembly of the instrument for generating a thermal sink sufficient to cause ablation of said tissue region, said cryoablation assembly being adapted to direct the majority of the thermal conduction generally in a predetermined direction across the distal end portion of the flexible tubular member.  
 
     
     
         57 . The system of  claim 56 , wherein 
 said decompression chamber is configured to generate said thermal sink substantially radially from a longitudinal axis of the cryoablation element, and said cryoablation assembly includes an elongated thermal isolating element extending partially around and generally in the direction of the longitudinal axis of the cryoablation element, said thermal isolating element defining an opening adapted to direct said majority of the thermal conduction generally in said predetermined direction.    
     
     
         58 . The system of  claim 56 , wherein 
 said flexible tubular member includes a key assembly to properly align the cryoablation assembly within the distal end portion of the flexible tubular member such that the predetermined direction of the majority of the thermal conduction aligns with the tissue region to be ablated.    
     
     
         59 . The system of  claim 1  wherein 
 said flexible tubular member is substantially transparent to allow visualization of the ablative device within said tubular member.  
 
     
     
         60 . The system of  claim 13  wherein 
 said flexible tubular member is made from a material which has a low loss tangent.  
 
     
     
         61 . The system of  claim 1  wherein 
 said flexible tubular member is made from a material which has a low water absorption coefficient.  
 
     
     
         62 . The system of  claim 16  wherein 
 said flexible tubular member is made from a material which has a low scattering coefficient.  
 
     
     
         63 . The system of  claim 19  wherein 
 said flexible tubular member is made from a material which has a electrical conductivity.  
 
     
     
         64 . The system of  claim 22  wherein 
 said flexible tubular member is made from a material working to provide a good mechanical impedance matching between the tissue and the ultrasound ablation element.  
 
     
     
         65 . The system of  claim 1 , wherein 
 said tubular member further includes a window portion in a portion of a side wall of the tubular member which extends longitudinally along at least a portion of the distal end portion of the tubular member.    
     
     
         66 . The system of  claim 65 , wherein 
 said energy delivery portion of the ablative device is configured to be exposed through the window portion of the tubular member for effecting ablation of tissue proximate to the window portion.    
     
     
         67 . The system of  claim 65 , wherein 
 said window portion is formed of a material used to obtain a good energy transfer between the ablative device and the tissue to ablate.    
     
     
         68 . The system of  claim 65 , wherein 
 said window portion is formed of a material with a low water absorption coefficient.    
     
     
         69 . The system of  claim 68 , wherein 
 said ablative device comprises at least one ultrasonic ablation element.    
     
     
         70 . The system of  claim 65 , wherein 
 said window portion comprises a removed portion of the side wall of the tubular member and wherein said ablative device comprises a ultrasonic ablation element.    
     
     
         71 . The system of  claim 65 , wherein 
 said window portion is formed of a laser transparent material and said ablative device comprises a laser emitting element.    
     
     
         72 . The system of  claim 65 , wherein 
 said window portion comprises a removed portion of the side wall of the tubular member and wherein said ablative device comprises a laser ablation element.    
     
     
         73 . The system of  claim 65 , wherein 
 said window portion is formed of a electrically conductive material and said ablative device comprises a RF ablation element.    
     
     
         74 . The system of  claim 65 , wherein 
 said window portion is formed of a dielectric material having a low loss-tangent at microwave frequencies and said ablative device comprises a microwave ablation element.    
     
     
         75 . The system of  claim 65 , wherein 
 said window portion comprises a removed portion of the side wall of the tubular member and wherein said ablative device comprises a microwave ablation element.    
     
     
         76 . The system of  claim 65 , wherein 
 said window portion comprises a removed portion of the side wall of the tubular member and wherein said ablative device comprises a microwave ablation element.    
     
     
         77 . The system of  claim 15 , wherein 
 said window portion is formed of a good thermal conductor material and said ablative device comprises a cryoablation element.    
     
     
         78 . The system of  claim 65 , wherein 
 said window portion comprises a removed portion of the side wall of the tubular member and wherein said ablative device comprises a cryoablation element.    
     
     
         79 . A system for ablating tissue within a body of a patient comprising: 
 an elongated flexible tubular member having at least one lumen and including a malleable distal end portion which is shaped to be positioned adjacent to or in contact with a selected tissue region within the body of the patient; and    an ablative device which is configured to be slideably received longitudinally within said at least one lumen and having an energy delivery portion located near a distal end portion of said ablative device which is adapted to be coupled to an ablative energy source.    
     
     
         80 . The system of  claim 79  wherein 
 said energy delivery portion and ablative energy source are working together to produce the ablation of said selected tissue region.  
 
     
     
         81 . The system of  claim 79  wherein 
 said distal end portion of the flexible tubular member has a distal end which is closed.  
 
     
     
         82 . The system of  claim 79  wherein 
 said energy delivery portion comprises a microwave ablation element.  
 
     
     
         83 . The system of  claim 82  wherein 
 said microwave ablation element is flexible.  
 
     
     
         84 . The system of  claim 82  wherein 
 said microwave ablation element is directional  
 
     
     
         85 . The system of  claim 79  wherein 
 said ablative device is a laser ablation element.  
 
     
     
         86 . The system of  claim 85  wherein 
 said laser ablation element is flexible.  
 
     
     
         87 . The system of  claim 85  wherein 
 said laser ablation element is directional.  
 
     
     
         88 . The system of  claim 79  wherein 
 said energy delivery portion comprises a radiofrequency ablation element.  
 
     
     
         89 . The system of  claim 88  wherein 
 said radiofrequency ablation element is flexible.  
 
     
     
         90 . The system of  claim 88  wherein 
 said radiofrequency ablation element is directional.  
 
     
     
         91 . The system of  claim 79  wherein 
 said energy delivery portion comprises an ultrasound ablation element.  
 
     
     
         92 . The system of  claim 91  wherein 
 said ultrasound ablation element is flexible.  
 
     
     
         93 . The system of  claim 91  wherein 
 said ultrasound ablation element is directional.  
 
     
     
         94 . The system of  claim 79  wherein 
 said energy delivery portion comprises an cryoablation element.  
 
     
     
         95 . The system of  claim 94  wherein 
 said cryoablation element is flexible.  
 
     
     
         96 . The system of  claim 94  wherein 
 said cryoablation element is directional.  
 
     
     
         97 . A system for ablating tissue within a body of a patient comprising: 
 an elongated rail device adapted to be positioned proximate and adjacent to a selected tissue region to be ablated within the body of the patient; and    an ablative device having a receiving passage configured to slideably receive said rail device longitudinally therethrough to slideably position the ablative device substantially adjacent to or in contact with the selected tissue region, said ablative device having an energy delivery portion which is adapted to be coupled to an ablative energy source.    
     
     
         98 . The system of  claim 97  wherein 
 said ablative device and ablative energy source are working together to produce the ablation of said selected tissue region.  
 
     
     
         99 . The system of  claim 97  wherein 
 said ablative energy source is a microwave generator and said ablative device includes a microwave ablation element.  
 
     
     
         100 . The system of  claim 97  wherein 
 said ablative energy source is a radiofrequency generator and said ablative device includes a radiofrequency ablation element.  
 
     
     
         101 . The system of  claim 97  wherein 
 said ablative energy source is a ultrasound generator and said ablative device includes a ultrasound ablation element.  
 
     
     
         102 . The system of  claim 97  wherein 
 said ablative energy source is a laser generator and said ablative device includes a laser ablation element.  
 
     
     
         103 . The system of  claim 97  wherein 
 said ablative energy source includes a compressor and a compressible gas, and said ablative device includes a cryoablation element.  
 
     
     
         104 . The system of  claim 97 , wherein 
 said rail device includes a pre-shaped distal portion.    
     
     
         105 . The system of  claim 97 , wherein 
 said rail device includes a malleable distal portion    
     
     
         106 . The system of  claim 97 , wherein 
 said ablative device is flexible.    
     
     
         107 . The system of  claim 97 , wherein 
 said ablative device is adapted to directionally emit the ablative energy from the energy delivery portion.    
     
     
         108 . The system of  claim 107  further including: 
 a key assembly cooperating between the ablative device and the rail member to properly align the directionally emitted ablative energy toward the tissue region to be ablated.  
 
     
     
         109 . The system of  claim 108 , wherein 
 the rail device includes a non-circular transverse cross-sectional dimension, and the receiving passage of the ablative device includes a substantially similarly shaped non-circular transverse cross-sectional dimension to enable sliding of the ablative device in a manner continuously aligning the directionally emitted ablative energy toward the tissue region to be ablated as the ablative device advances along the rail device.    
     
     
         110 . The system of  claim 109 , wherein 
 the transverse cross-sectional dimensions of the rail device and the receiving passage are rectangular-shaped.    
     
     
         111 . The system of  claim 109 , wherein 
 the transverse cross-sectional dimensions of the rail device and the receiving passage are oval-shaped.    
     
     
         112 . The system of  claim 108 , wherein 
 one of the rail device and an interior wall, defining receiving passage of the ablative device, includes a key notch, and the other of the interior wall and the rail device defines a matching keyway to continuously align the directionally emitted ablative energy toward the tissue region to be ablated as the ablative device advances along the rail device.    
     
     
         113 . The system of  claim 108  wherein 
 said energy delivery portion is provided by a microwave ablation element.  
 
     
     
         114 . The system of  claim 113  wherein 
 said microwave ablation element comprises a microwave antenna which is located within an antenna assembly of the ablative device for generating an electromagnetic field sufficient to cause ablation of said tissue region, said antenna assembly being adapted to direct the majority of the electromagnetic field generally in a predetermined direction across the distal end portion of the flexible tubular member.  
 
     
     
         115 . The system of  claim 114  wherein 
 said antenna is configured to generate said electromagnetic field substantially radially from a longitudinal axis of the antenna, and said antenna assembly includes an elongated shield extending partially around and generally in the direction of the longitudinal axis of the antenna, said shield defining an opening adapted to direct said majority of the electromagnetic field generally in said predetermined direction.