Acute ascending aortic dissection is a life-threatening condition. Current standard of treatment is with open cardiac surgery (Malaisrie et al, J Thorac Cardiovasc Surg 162(3):735–758.e2, 2021). However, up to one-third of patients are deemed unfit for open surgery and therefore are subject to the 57% mortality associated with medical management (Nordon et al, Eur J Vasc Endovasc Surg 44(4):406–410, 2012; Evangelista et al, Circulation 137(17):1846–1860, 2018; Inoue et al, Ann Thorac Surg 110(3):790–798, 2020). Thoracic endovascular aortic repair (TEVAR) has become an effective and well-established first-line treatment for descending thoracic aortic dissection and is beginning to be explored as a potential option for high-risk patients with ascending aortic pathology including acute dissection who may be considered to be at prohibitive risk for open repair (MacGillivray et al, Ann Thorac Surg, 2022; Roselli et al, J Endovasc Ther, 2022). Technical considerations specific to the endovascular treatment of acute type A dissection are given throughout the chapter.