A method of treating a tissue region includes inserting a flexible sheath within a vessel, the vessel leading to a tissue region, placing a distal end of the sheath through a wall of the vessel to thereby position the distal end is at or adjacent the tissue region, deploying a plurality of electrodes from the distal end of the sheath such that tips of the deployed electrodes approximately face towards a proximal end, and delivering energy to the tissue region using the deployed electrodes.
