The purpose of this post-approval study is to evaluate the long-term performance of the GORE TAG® Thoracic Endoprosthesis (TAG device) in the primary treatment of descending thoracic aortic (DTA) aneurysms

Inclusion Criteria:

1. Descending thoracic aortic aneurysm deemed to warrant surgical repair:

   1. Fusiform aneurysm greater than or equal to 2 times diameter of normal adjacent aorta
   2. Saccular aneurysm

2. Anatomy meets GORE TAG Thoracic Endoprosthesis specification criteria as indicated in the Instructions for Use (Appendix A)

3. Minimum 2 cm non-aneurysmal segment proximal and distal to the aneurysm

   • <60 degree angle in the aortic arch may require additional length of non-aneurysmal segment if the arch is included in the treatment segment

4. Life expectancy > 2 years

5. Surgical Candidate

   • ASA Class I, II, III, or IV
   • NYHA Class I, II, III or no heart disease

6. Male or infertile female

7. Minimum 21 years of age

8. Able to comply with protocol requirements

9. Signed Informed Consent Form

Exclusion Criteria:

1. 4 mm aortic taper and inability to use devices of different diameters, to compensate for the taper, in the treatment area of the aorta
2. Significant thrombus at the proximal or distal implantation zones
3. Mycotic aneurysm
4. Hemodynamically unstable aneurysm rupture (non-contained aneurysm rupture)
5. Acute or chronic aortic dissection
6. Planned occlusion of the left carotid or celiac arteries
7. "Planned" concomitant surgical procedure (other than left subclavian transposition) or previous major surgery within 30 days
8. Myocardial infarction or cerebral vascular accident within 6 weeks
9. Severe respiratory insufficiency sufficient that precludes open thoracotomy
10. Renal insufficiency (Creatinine > 2.0 mg/dL) with or without dialysis
11. Degenerative connective tissue disease, e.g., Marfan or Ehler-Danlos Syndrome
12. Participation in another investigational device or drug study within 1 year
13. Documented history of drug abuse within 6 months