A vessel dissector for harvesting a target vessel from a donor has a generally cylindrical tip body with a sloping channel formed along a longitudinal side. A channel bottom provides a channel depth that decreases from a distal channel end to a proximal channel end. The tip body has a crescent-shaped forward lip extending distally from the channel. An arcuate collar is slidably disposed in an arcuate recess within the tip body to selectably bridge the channel at the distal end of the channel to form a ring profile with the forward lip. A first ferromagnetic heating element is disposed along a radially outward surface of the forward lip. A second ferromagnetic heating element is disposed on a distal edge of the arcuate collar. The first and second ferromagnetic heating elements are adapted to be energized simultaneously to make a vasiform cut including a pedicle around the target vessel.