One or more markers or sensors (electromagnetic coils 106a,106b,106c,706) are positioned in the vasculature of a patient to facilitate determining the location, configuration, and/or orientation of a vessel or certain aspects thereof (e.g., a branch vessel), determining the location, configuration and/or orientation of a endovascular devices prior to and during prosthesis deployment as well as the relative position of portions of the vasculature and devices, generating an image of a virtual model of a portion of one or more vessels (e.g., branch vessels) (BV1,BV2) or devices, and/or formation of one or more openings in a tubular prosthesis in situ to allow branch vessel perfusion when the prosthesis is placed over one or more branch vessels in a patient (e.g., when an aortic abdominal artery stent-graft is fixed to the aorta superior to the renal artery ostia).