Thoracic endovascular aortic repair (TEVAR) is a rapidly evolving new therapy in the treatment of thoracic aneurysms and dissections. TEVAR involves placing an endovascular stent graft into the thoracic aorta from a remote peripheral location under imaging guidance. Because it is less invasive than traditional thoracotomy with direct operative repair, TEVAR has the potential to revolutionize the treatment of thoracic aneurysms, similar to the development of prosthetic grafts for open repair.

TEVAR offers potential for durable aneurysm exclusion while avoiding thoracotomy and aortic crossclamping. Nevertheless, stroke, spinal cord ischemia, and other complications that are associated with open repair can also occur with TEVAR.

Up 40% of patients undergoing TEVAR have pathology that extends near the left subclavian artery (LSA). In these situations, currently approved devices are typically placed over the LSA origin, thereby occluding this arch vessel. Some surgeons routinely perform LSA revascularization in these patients, whereas others do in certain circumstances, particularly when there is a dominant left vertebral artery (60% of patients), a previous left internal mammary coronary artery bypass graft, or the distal right vertebral segment is absent. Finally, some surgeons do not perform LSA revascularization when this artery is covered unless symptoms develop after TEVAR.

Published reports show the baseline risks of adverse outcomes in patients who have TEVAR and LSA coverage are 6% arm ischemia, 4% spinal cord ischemia, 2% vertebrobasilar ischemia, 5% anterior circulation stroke, and 6% death. Treatments that reduce these risks are important to characterize.