Evaluation of the Valiant Mona LSA Thoracic Stent Graft System in Descending TAA and Chronic Dissections

Inclusion Criteria for Thoracic Aortic Aneurysms and Penetrating Ulcers: * Subject is at least 18 years of age. * Subject understands and has signed an Informed Consent approved by the Sponsor and by the IRB for this study. * Subject must be considered a candidate for revascularization of the LSA. Subject must be able to tolerate a surgical revascularization of the LSA. * Subject has a TAA/PAU which will require coverage of the LSA and is: * a fusiform aneurysm with a diameter of ≥ 5.5 cm OR is \> 2 times the diameter of the non-aneurysmal thoracic aorta; AND/OR * a saccular aneurysm or PAU (ulcer defined as ≥ 10 mm in depth and 20 mm in diameter, or symptomatic) * Subject has a healthy, non-diseased aortic proximal seal zone of at least 20 mm from the distal end of the LCC ostium to the beginning of the disease, including at least 10 mm between the LSA and the LCC. * Subject has a non -diseased aortic proximal neck length of \>0mm distal to the LSA * Subject has a non-diseased aortic diameter between 25 mm and 42 mm * Subject has a non-diseased LSA with a diameter between 8 mm and 13 mm. * Subject has sufficient landing zone within the LSA to accommodate the BSG without occlusion of any significant vessels * Brachial, iliac or femoral artery access vessel morphology (diameter, calcification, tortuosity) that is compatible with vascular access techniques, the device, or accessories. * Introducer sheath is required for all procedures. * An iliac conduit is required …