Patent ID: 8216224

Claim:
A method of controlling an ablation volume depth during surface treatment of a target tissue site, the method comprising: providing a tissue surface treatment apparatus, the apparatus comprising: a housing having a proximal end and a distal end comprising a conformable tissue contacting surface having at least one aperture, wherein the conformable tissue contacting surface is positioned distally of the distal end of the housing the housing defining an interior; an energy delivery device positionable in the housing interior, the energy delivery device including at least one electrode with a tissue penetrating distal end, the at least one electrode configured to be advanced from the housing interior through the at least one aperture and into a target tissue site to define an ablation volume at least partly bounded by the tissue surface; an advancement device coupled to the energy delivery device, the advancement device configured to advance the at least one electrode from the housing interior to a selected deployment depth; positioning the tissue contacting surface on a target tissue surface, wherein the tissue surface has at least one contour; manipulating the tissue contacting surface to at least partially conform the tissue contacting surface to the at least one contour of the target tissue surface; advancing the at least one electrode to the selected deployment depth beneath a tissue surface while avoiding at least one critical structure; delivering ablative energy from the energy delivery device; creating an ablation volume at a controlled depth below the tissue surface responsive to the electrode deployment depth; and minimizing injury to the at least one critical structure responsive to the electrode deployment depth.