A system and method for surface tissue ablation on the patient's outer
skin, such as the epidermis or the underlying dermis. An electrosurgical
probe (130) comprises a shaft (132) having an array of active electrodes
(136) on its distal tip and a connector (134) at its proximal end for
coupling the electrode array to a high frequency power supply. An
electrically conducting liquid is directed along a fluid flow path (142)
past a return electrode surface (138) to the target site to provide a
current flow path between the target site and the return electrode. High
frequency voltage is then applied to the active and return electrodes so
that an electric current flows from the active electrode, through a layer
of vapor formed at the tip of the electrode, and to the return electrode
through the current flow path provided by the electrically conducting
liquid. The high frequency voltage will preferably be sufficient to
establish high electric field densities between the active electrode
array and the epidermal tissue to thereby induce molecular breakdown or
disintegration of several cell layers of the tissue.