Staging such procedures is common, particularly to address aortic branch points near the diseased aortic segment. One example in the treatment of thoracic aortic disease is revascularization of the left common carotid artery and/or the left subclavian artery from the innominate artery or the right common carotid artery to allow treatment of a thoracic aortic aneurysm that encroaches proximally into the aortic arch. These "extra-anatomic bypasses" can be performed without an invasive thoracotomy. Another example in the abdominal aorta is the embolization of the internal iliac artery on one side prior to coverage by an iliac limb device. Continued improvement in stent graft design, including branched endografts, will reduce but not eliminate multi-stage procedures.