Apparatuses and Methods for Interstitial Tissue Removal
Apparatuses and methods for removing solid tissue from beneath a tissue surface are described. The methods rely on positioning an energy conductive element at a target site beneath the tissue surface and energizing the element so that it can vaporize tissue. The element is then moved in a pattern which provides the desired tissue removal geometry, such as spherical, ovoid, or cylindrical. Usually, the shaft is moved, typically rotated or reciprocated, and the energy conductive element is moved relative to the shaft, typically by pivoting a rigid element or bowing a flexible element.
1 . A tissue ablation device comprising:
a shaft having a proximal end, a distal end, and a lumen therethrough,
a substantially rigid energy conductive straight cylindrical pin attached to pivot about a fixed point on the shaft near its distal end;
a means for causing the element to pivot relative to the shaft; and
an aspiration connector coupled to the lumen near the proximal end of the shaft.
2 . The tissue ablation device of claim 1 , further comprising:
a power supply connector disposed near the proximal end of the shaft and electrically coupled to the energy conductive element.
3 . The tissue ablation device of claim 2 , further comprising a handle positioned at the proximal end of the shaft.
4 . The tissue ablation device of claim 3 , wherein the aspiration connector and the power supply connector are disposed on the handle.
5 . The tissue ablation device of claim 1 , further comprising:
a motor attachable to the proximal end of the shaft.
6 . The tissue ablation device of claim 5 , wherein the motor is adapted to both rotate the shaft and move the substantially rigid energy conductive straight cylindrical pin relative to the shaft.
7 . The tissue ablation device of claim 1 , wherein the substantially rigid energy conductive straight cylindrical pin comprises an electrode that conducts high frequency electrical energy.
8 . The tissue ablation device of claim 1 , wherein the substantially rigid energy conductive straight cylindrical pin comprises a heating element.
9 . The tissue ablation device of claim 8 , wherein the heating element comprises an optical fiber configured to deliver light energy to heat the energy conductive element.
10 . The tissue ablation device as in claim 8 , wherein the heating element comprises an electrical resistance heater.
11 . The tissue ablation device of claim 1 , wherein the substantially rigid energy conductive straight cylindrical pin is pivotally attached near its middle to the shaft.
12 . The tissue ablation device of claim 1 , wherein the substantially rigid energy conductive straight cylindrical pin is pivotally attached near one end thereof to the shaft.
13 . A method for performing tissue ablation comprising:
positioning an energy conductive element situated at a distal end of a shaft at a target tissue site;
operating a drive mechanism coupled to the conductive element to bow the conductive element between a substantially linear profile where the element lies directly over the shaft and a series of arcuate profiles continuously spaced progressively away from the shaft, thereby providing a continuous series of arcuate tissue removal paths;
while operating said drive mechanism, rotating the conductive element about the shaft and applying energy to the conductive element, thereby vaporizing all tissue in the path of the conductive element; and
while vaporizing said tissue, applying an aspiration source to a lumen included within the shaft, said lumen coupled to the distal end of the shaft in a region including the conductive element, and thereby withdrawing vaporized tissue from the target tissue site.
14 . The method of claim 13 , further comprising:
imaging the target tissue site and positioning the conductive element based on the image.
15 . The method of claim 14 , wherein the conductive element is manually positioned in real time by a user who is viewing the image.
16 . The method of claim 14 , wherein the conductive element is automatically positioned by a positioning system in response to the image.
17 . The method of claim 13 , wherein applying energy to the conductive element comprises delivering high frequency electrical current.
18 . The method of claim 17 , wherein the high frequency electrical current is delivered in a bipolar manner between the conductive element and an electrode positioned at or near the target tissue site.
19 . The method of claim 17 , wherein the high frequency electrical current is delivered in a monopolar manner between the conductive element and a skin pad on the patient's outer skin.
20 . The method of claim 17 , wherein applying energy to the conductive element comprises heating the element.