An intravascular catheter for nerve activity ablation and/or sensing includes one or more needles advanced through supported guide tubes (needle guiding elements) which expand to contact the interior surface of the wall of the renal artery or other vessel of a human body allowing the needles to be advanced though the vessel wall into the extra-luminal tissue including the media, adventitia and periadvential space. The catheter also includes structures which provide radial and lateral support to the guide tubes so that the guide tubes open uniformly and maintain their position against the interior surface of the vessel wall as the sharpened needles are advanced to penetrate into the vessel wall. Electrodes at the distal ends of the guide tubes allow sensing of nerve activity before and after attempted renal denervation. In a combination embodiment ablative energy or fluid is delivered to ablate nerves outside of the media.
