Ablation system with impedance navigation

A method of ablating tissue, the method comprising:

• obtaining an ablation system having an inner coil electrode with an outer surface and an inner pitch, an outer coil electrode with an inner surface and an outer pitch, a first guide needle with a first guide axis, a second guide needle with a second guide axis;
• and, a hub having a first ablation template with a first outer electrode port adapted for receiving the outer coil electrode, a first inner electrode port adapted for receiving the inner coil electrode, a first guide port for receiving the first guide needle, and a second guide port for receiving the second guide needle;
• wherein, the outer electrode is configured as an impedance electrode;
• locating a tissue for ablation;
• aligning the first ablation template over the tissue;
• receiving the first guide needle in the first guide port of the first ablation template;
• inserting the first guide needle into the tissue;
• receiving the second guide needle in the second guide port of the first ablation template;
• inserting the second guide needle into the tissue;
• creating an annular ablation region in the tissue to be ablated, the creating including receiving the inner coil electrode in the first inner electrode port of the first ablation template;
• receiving the outer coil electrode in the first outer electrode port of the first ablation template;
• inserting the outer coil electrode into the tissue, the inserting including slidably translating the luminal surface of the outer coil electrode around the first guide needle and the second guide needle, wherein the outer coil electrode surrounds the first guide needle and the second guide needle;
• the inserting including navigating the penetration of the outer electrode into the tissue, the navigating including monitoring the electrical impedance of the tissue with the position of the outer coil electrode;
• inserting the inner coil electrode into the tissue, the inserting including slidably translating the outer surface of the inner coil electrode concentric with the outer coil electrode to create the annular ablation region;
• wherein, the first guide needle and the second guide needle are in the annular ablation region, securing the tissue and guiding the dual coil ablation system into the tissue for the ablation, the securing and the guiding facilitated by the first guide needle and the second guide needle, removing the first guide needle and the second guide needle from the tissue, and, ablating the tissue by delivering energy through the inner and outer coils.

A method of ablating a prostate tissue of a subject, comprising:

• obtaining an ablation device having
• an outer coil electrode having an inner diameter ranging from 4 mm to 40 mm, a lumen having a luminal surface forming the inner diameter, an outer length, and an outer coil axis;
• wherein, the outer electrode is configured as an impedance electrode;
• an inner coil electrode having an outer diameter that ranges from 2 mm to 39 mm and is 1.0 mm to 38.0 mm smaller than the inner diameter of the outer coil electrode, an outer surface, an inner length, and an inner coil axis;
• a plurality of guide needles including
• a first guide needle having a first guide axis and a first guide length;
• and,
• a second guide needle having a second guide axis and a second guide length;
• and,
• a hub having a first ablation template, the first ablation template including a first outer electrode port adapted for receiving the outer coil electrode, a first inner electrode port adapted for receiving the inner coil electrode, a first guide port for receiving the first guide needle, and a second guide port for receiving the second guide needle;
• locating the prostate tissue for ablation;
• aligning the first ablation template over the prostate tissue;
• receiving the first guide needle in the first guide port of the first ablation template;
• inserting the first guide needle into the prostate tissue;
• receiving the second guide needle in the second guide port of the first ablation template;
• inserting the second guide needle into the prostate tissue;
• creating an annular ablation region in the prostate tissue, the creating including
• receiving the inner coil electrode in the first inner electrode port of the first ablation template, and receiving the outer coil electrode in the first outer electrode port of the first ablation template;
• inserting the outer coil electrode into the prostate tissue, the inserting including slidably translating the luminal surface of the outer coil electrode around the first guide needle and the second guide needle, wherein the outer coil electrode contains the first guide needle and the second guide needle;
• wherein the inserting includes monitoring the electrical impedance of the outer coil electrode as it is advanced into the subject to position of the outer coil electrode in the prostate tissue while avoiding any tissue not intended to be ablated;
• inserting the inner coil electrode into the prostate tissue, the inserting including slidably translating the outer surface of the inner coil electrode concentric with the outer coil electrode to create the annular ablation region;
• wherein, the first guide needle and the second guide needle are in the annular ablation region, securing the tissue and guiding the dual coil ablation system into the tissue for the ablation, the securing and the guiding facilitated by the first guide needle and the second guide needle, removing the first guide needle and the second guide needle from the tissue, and, ablating the tissue by delivering energy through the inner and outer coils.