On March 23, 2005, the U.S. Food and Drug Administration (FDA) approved the Gore TAG thoracic endoprosthesis. Since then, two other thoracic stent graft systems have received approval: the Medtronic Talent (Medtronic Vascular, Santa Rosa, CA, USA) and the Zenith TX-2 (Cook Medical Inc, Bloomington, IN, USA). Currently, the only FDA-approved indication for the use of these devices is for the treatment of thoracic aortic aneurysmal disease. However, endovascular stents are now being successfully used for other aortic pathology such as acute and chronic dissection, transection, and aorto-bronchial fistulae. The early results have been very promising, and long-term data on durability are awaited.73 In aneurysmal disease, the goal of the stent is to exclude the aneurysmal sac so that further dilation and disease progression can be prevented. In aortic dissection, the goal of the sent is to exclude the intimal tear, thus preventing its evolution. During an EVAR procedure, TEE is extremely valuable and can be used to verify pathology such as the site of the intimal tear, to identify the true and false lumen, to guide stent placement, to detect endoleaks, and to assess cardiac performance.74 It can also be used to take measurements of the aorta and the aortic lesion, document side branch patency, and detect static or dynamic obstruction. An added benefit of TEE is the noninvasive visualization and direction of guidewires and catheters on short- and long-axis views of the aorta, thus reducing the need for nephrotoxic contrast agents. A guidewire appears as a linear echo-dense intraluminal structure. TEE is also an excellent hemodynamic monitor, especially during inflation of the balloon to unfold the stent. Similar to cross-clamping of the aorta, inflation of the balloon can cause significant aortic occlusion and subsequent strain on the heart, and result in regional or global myocardial ischemia. Newer endoaortic balloons, however, incorporate a nonocclusive design that permits partial flow, thereby reducing the extent of myocardial strain. However, TEE use is limited by the poor visualization of the distal ascending aorta and proximal arch, and by the need for general anesthesia. There is also the potential interference of the TEE probe with fluoroscopy during procedures in the aortic arch.