A device for extending, elongating, or repairing a previously created arteriovenous fistula between a first blood vessel and an adjacent second blood vessel includes a main body having a primary lumen and an articulating jaw member disposed at the distal end of the main body. The jaw member is configured with two elements to allow rotation of one element about a pivot point to grasp tissue while being rotated. The jaw member is also configured to allow thermal energy delivery to one or both elements of the jaw member that allow tissue welding and cutting with DC, RF, Laser or Ultrasonic energy. A second lumen located within one element of the jaw member is configured to allow advancement over a guidewire into the second vessel while the other element of the jaw member remains within the first blood vessel at the position where the arteriovenous fistula, or aperture, exists between the first and second blood vessel.
