A peripheral vessel tissue modification system includes a first longitudinal member, a second longitudinal member, and a radiofrequency energy source. The first member is configured for advancement into a peripheral vessel of a patient, is coupled to the energy source, and extends along a length between a proximal end and a distal end. The first member includes an inner lumen extending along its length and a distal electrode located on an outer surface proximate to the distal end and electrically coupled to the energy source. The second member is configured for insertion into the vessel through the lumen, is coupled to the energy source, and extends along a length between a proximal end and a distal end including a tip electrode. The second member is moveable with respect to the first member to create a bipolar arrangement between the distal electrode and the tip electrode for delivery of radiofrequency energy.
