Methods and apparatus for a percutaneous bypass graft system according to various aspects of the present technology include a graft section comprising a dual-sided fixation system at the anastomosis site and a tamper sheath configured to provide enhanced control during installation. The dual-sided fixation system may comprise a plurality of barbs configured to secure the graft section to an internal and external portion of a target vessel. The tamper sheath comprises a cuff at a distal end that is configured to be positioned against an outer surface of the target vessel during the percutaneous procedure.