Safety and Efficacy of Valiant Mona LSA Stent Graft System

Inclusion Criteria: * Subject is at least 18 years of age. * The subject or legal guardian understands the nature of the study and agrees to its provisions on a written informed consent form * Subject must be considered a candidate for revascularization of the LSA. * Subject has a DTA which will require coverage of the LSA * Subject's anatomy must meet the anatomical criteria to receive that implanted device Exclusion Criteria: * Subject has had previous endovascular repair of the ascending and/or descending thoracic aorta. * Subject is in acute renal failure or has renal insufficiency with a serum creatinine ≥ 2.0 mg/dL * Subject is a pregnant female. * Enrollment in another clinical study * Subject has had a cerebral vascular accident (CVA)or myocardial infarction (MI) within 3 months. * Subject has a history of bleeding diathesis, coagulopathy, or refuses blood transfusion. * Subject has a known allergy or intolerance to the device components. * Subject has a known hypersensitivity or contraindication to anticoagulants or contrast media, which is not amenable to pre-treatment.