An ultra-sonic medical dissector includes a vibration generator and a wire that defines a cutting loop remote from a first end and a second end. The wire is coupled to the vibration generator in a cutting configuration, and a cutting surface is located on an inner curvature of the cutting loop. A vibration is generated by the vibration generator is transmitted to the cutting loop by the wire when the wire is in tension. The cutting loop can free an embedded end of a vena cava filter from a vessel wall to ease retrieval.