Cooled bipolar radio-frequency ablation probe

A cooled radio-frequency (RF) ablation probe comprising:

• a proximal end, an opposite distal end, and a length extending between the proximal end and the distal end;
• a first tubular portion extending between the proximal end and the distal end, the first tubular portion defining at least part of an internal cavity for circulating coolant through the cooled RF ablation probe;
• a second tubular portion surrounding the first tubular portion along a first portion of the length of the cooled RF ablation probe;
• a third tubular portion surrounding the second tubular portion along a second portion of the length of the cooled RF ablation probe;
• a fourth tubular portion surrounding the third tubular portion along a third portion of the length of the cooled RF ablation probe;
• a tip portion provided at and adjacent the distal end, a portion of the tip portion defining at least part of the internal cavity;
• and
• at least one temperature sensor provided within or on a portion of the fourth tubular portion;
• wherein at least a portion of the tip portion serves as an active electrode, and at least a portion of the third tubular portion serves as a return electrode;
• and
• wherein a gap is defined between the third tubular portion and the fourth tubular portion that extends between a first position and a second position along the length of the RF ablation probe, the first position being closer to the proximal end than the second position, the gap being blocked off at or adjacent the first position and at or adjacent the second position so that the gap can be filled with air or a vacuum can be formed in the gap.

A cooled radio-frequency (RF) ablation probe comprising:

• a proximal end, an opposite distal end, and a length extending between the proximal end and the distal end;
• a collar portion positioned at least adjacent the proximal end;
• a first tubular portion extending from the collar portion toward the distal end, the first tubular portion defining at least part of an internal cavity for circulating coolant through the cooled RF ablation probe;
• a second tubular portion surrounding the first tubular portion along a first portion of the length of the cooled RF ablation probe;
• a third tubular portion surrounding the second tubular portion along a second portion of the length of the cooled RF ablation probe;
• a fourth tubular portion surrounding the third tubular portion along a third portion of the length of the cooled RF ablation probe;
• a coolant supply line extending from the collar portion through at a first portion of the internal cavity toward the distal end, the coolant supply line configured to expel the coolant into the internal cavity;
• a tip portion provided at and adjacent the distal end, the tip portion being spaced apart from the third tubular portion by a portion of the second tubular portion, and a portion of the tip portion being received within the first tubular portion to block off the internal cavity defined at least in part by the first tubular portion;
• and
• at least one monitoring thermocouple provided within or on a portion of the fourth tubular portion;
• wherein at least a portion of the tip portion serves as an active electrode, and at least a portion of the third tubular portion serves as a return electrode;
• and
• wherein a gap is defined between the third tubular portion and the fourth tubular portion that extends between a first position and a second position along the length of the RF ablation probe, the first position being closer to the proximal end than the second position, the gap being blocked off at or adjacent the first position and at or adjacent the second position so that the gap can be filled with air or a vacuum can be formed in the gap.