The disclosure pertains to an intravascular catheter, comprising an elongate member having a proximal end and a distal end, a balloon having an interior surface, an exterior surface, a lumen defined by the interior surface and a cylindrical wall extending between the interior surface and the exterior surface, the cylindrical wall having a proximal end and a distal end, the balloon having a plurality of weeping windows disposed in the wall and able to pass an electric current between the interior surface and the exterior surface and wherein the balloon wall is otherwise electrically insulative, and an electrode disposed in the balloon. The intravascular system is suited for modulation of renal nerves, for example.