In selected patients who have an anatomy that compromises perfusion to the brain, spinal cord, heart, or left arm, routine preoperative LSA revascularization is strongly recommended. Some of these conditions are:

• Presence of a patent left internal mammary artery to coronary artery bypass graft
• Termination of the left vertebral artery at the posterior inferior cerebellar artery or other discontinuity of the vertebrobasilar collaterals
• Absent or diminutive or occluded right vertebral artery
• A functioning arteriovenous shunt in the left arm
• Prior infrarenal aortic repair with ligation of lumbar and middle sacral arteries
• Planned long-segment (20 cm) coverage of the descending thoracic aorta where critical intercostal arteries originate
• Hypogastric artery occlusion
• Presence of early aneurysmal changes that may require subsequent therapy involving the distal thoracic aorta