Apparatus and methods for ablating, severing,
cutting, shrinking, coagulating, or otherwise modifying a
target tissue to be treated. In a method for treating a
target tissue, an
active electrode of an electrosurgical probe is positioned in at least close proximity to the
target tissue in the presence of an
electrically conductive fluid. A
high frequency voltage is then applied between the
active electrode and a return
electrode, wherein, the
high frequency voltage is sufficient to volumetrically remove (ablate), sever, or modify at least a portion of the target tissue. The probe comprises a multi-lumen shaft having a plurality of internal lumens, and a return
electrode coil oriented substantially parallel to the shaft distal end. The
active electrode may be in the form of a
metal disc, a hook, or an active
electrode coil. In the latter embodiment, the active electrode coil is typically arranged substantially orthogonal to the return electrode coil. Methods of making an active electrode coil, a return electrode coil, and an electrosurgical probe are also disclosed.