Feasibility of Endovascular Repair of Ascending Aortic Pathologies

Inclusion Criteria: * In order to qualify for this physician-sponsored Investigational Device Exemption, the patients would have to meet the entire entry criteria listed below, sign a consent approved by the FDA and IRB, and agrees to follow-up according to the study protocol. * Patient must have a type A thoracic aortic dissection, retrograde type A thoracic aortic dissection of the ascending thoracic aorta affecting the area between the Sinus of Valsalva and the innominate artery orifice (with no involvement of the aortic valve) and be considered a candidate for endovascular repair; * The proximal and distal landing zones for placement of graft should be at least 1 cm. * The proximal landing zone will allow placement of the stent graft as to not inhibit valvular function, occlude a coronary ostium or proximal bypass graft; The aortic root may be dissected, but the proximal tear site must be at least 1cm from the STJ (and within the above listed size criteria). * Distal landing zone must allow for continued perfusion of critical cerebral vessels; * The aorta as measured adventitial wall to adventitial wall must be greater than 28 mm and no more than 44 mm maximum diameter at both the proximal and distal landing zone. * The patient must be high-risk surgical candidate according to the following established criteria: ASA score of IV. Exclusion Criteria: * Pregnant or pediatric patients (younger than 21 years of age); * Patients who have a condition that threatens to infect the stent graft/aortic valve prosthesis; * Patients with allergies to the stent graft material; * Patients or their legally authorized representative (LAR) who do not sign the informed consent; * Patients with expected survival less than one year due to a condition other than the ascending aortic