Thoracic Endoprosthesis for Treatment of Aneurysm of the Descending Thoracic Aortic

Inclusion Criteria:\> 1\. Presence of DTA aneurysm deemed to warrant surgical repair \> * Fusiform (≥50 mm), or \> * Saccular (no diameter criteria)\> 2. Subject is \> 21 years of age\> 3. Proximal and distal landing zone length ≥ 2.0 cm \> * Landing zones must be in native aorta\> * Landing zone may include left subclavian artery, if necessary\> 4. All proximal and distal landing zone inner diameters are between 16-42 mm\> * Diameter assessed by flow lumen and thrombus, if present; calcium excluded\> 5. Life expectancy \> 2 years\> 6. Able to tolerate thoracotomy \> 7. Male or infertile female\> 8. Able to comply with protocol requirements including following-up\> 9. Signed informed consent\> Exclusion Criteria:\> 1. Differing proximal and distal neck diameters (aortic taper) outside the intended aortic diameter requirements (sizing guide) for a single endoprosthesis diameter and the inability to use devices of different diameters (in adherence to the sizing guide) to compensate for the taper\> 2. Tortuous or stenotic iliac and/or femoral arteries and inability to use a conduit for vascular access\> 3. Aneurysmal, dissected, heavily calcified, or heavily thrombosed landing zone(s)\> 4. Mycotic aneurysm\> 5. Hemodynamically unstable aneurysm rupture\> 6. Aortic dissection\> 7. Planned coverage of left carotid or celiac arteries with the CTAG Device\> 8. Planned concomitant surgical procedure (other than left subclavian transposition and wireless sac pressure monitoring), or major surgery within 30 days of treatment date\> 9. Known degenerative connective tissue disease, e.g. Marfan or Ehler-Danlos Syndrome\> 10. Known history of drug abuse\> 11. ASA risk classification = V (moribund patient not expected to live 24 hours with or without operation)\> 12. NYHA class IV \> 13. Participating in another investigational device or drug study within 1 year of treatment\> 14. Subject has known sensitivities or allergies to the device materials\> 15. Subject has a systemic infection and may be at increased risk of endovascular graft infection\>