Abstract: An apparatus, system, and method for treating body tissue includes an electrode assembly having a first electrode and a second electrode, with at least the first electrode formed of a foam-like material. Conductive fluid is delivered to the operating site, which may involve injecting the conductive fluid through the porous foam-like material of the first electrode via a fluid supply conduit. The apparatus may also include a fluid withdrawal conduit. The second electrode may also be formed of a foam-like material. The electrode assembly may be positioned on a catheter shaft having a distal end, with the first electrode positioned on the catheter shaft distal end. In treating desired tissue at a selected operational site, the electrode assembly is introduced to the site with one or more of the first electrodes positioned adjacent to the desired tissue. Conductive fluid, such as a saline solution, is delivered to the operational site via the supply conduit.