Branched Thoracic Endovascular Grafts for the Treatment of Thoraco-abdominal Aortic

Inclusion Criteria All patients must meet all of the following inclusion criteria to be eligible for enrollment into this study: 1. Patient is \> 18 years of age 2. Patients who are male or non-pregnant female (females of child bearing potential must have a negative pregnancy test prior to enrollment into the study. 3. Patient or Legally Authorized Representative has signed an Institutional Review Board (IRB) approved Informed Consent Form 4. Patient is considered by the treating physician and a second attending physician experienced in the care of patients with aneurysmal disease to be at high risk of open surgical repair due to one or more major medical co-morbidities (i.e. CAD, CHF, COPD, CRI, advanced age, generalized deconditioning, or other.) with ASA of 3 or more. 5. The patient has reasonable expectation of surviving the B-TEVAR procedure and has a life expectancy of greater than 1 year as determined by the PI and a second attending physician experienced in the care of patients with aneurysmal disease. 6. The patient has a thoraco-abdominal aortic aneurysm where necessary visceral branch vessels (i.e. the celiac, superior mesenteric, inferior mesenteric, renal and/or dominant spinal arteries) arise from the aneurysm or seal zones necessary for on-label thoracic endovascular repair 7. Patient has a thoraco-abdominal aortic aneurysm that meets at least one of the following: * aneurysm \> 5.5 cm in diameter * aneurysm has increased in size by 0.5 cm in last 6 months * aneurysm is believed to be causing symptoms 8. Patient has sufficient arterial access (femoral and/or iliac) that will allow delivery of the endovascular device with or without the use of a surgical conduit. 9. Patient has suitable proximal (aorta) and distal (aorta or iliac) arteries to allow for adequate fixation and seal: A. Non-aneurysmal proximal aortic seal zone: 1. Standard BTEVAR cohort will require a length of 25 mm of proximal seal in non-aneurysmal aorta, with or without coverage of the left subclavian artery. 2. The BTEVAR-CTD cohort will require a length of 30 mm of proximal seal with an outer wall diameter of no less than 15 mm and no greater than 42 mm, and 3. B. Non-aneurysmal distal aortic or iliac landing zone: 4. With a length of at least 15 mm, 5. Aortic seal zone no less than 15 mm and no greater than 42 mm or 6. Iliac seal zone with an outer wall diameter of no less than 8 mm and no greater than 23 mm. 10\. The patient has no more than 5 necessary visceral arteries that require flow preservation. 11\. All target visceral artery seal zones are \> 4 mm in diameter. 12. Patient must be willing to comply with all required follow-up exams. 5.1.2 Exclusion Criteria Patients that meet ANY of the following are not eligible for enrollment into the study: 1. Patient has an active systemic infection 2. Patient has a mycotic aneurysm. 3. Patient has a known hypersensitivity to contrast media that is not amenable to pre- treatment. 4. Patient has an absolute contra-indication to anticoagulation 5. Patient has known sensitivities or allergies to nitinol (nickel, titanium), polyester, polypropylene, gold, 1\. stainless steel, or solder (tin, silver) 6. Patient has a body habitus that would inhibit adequate X-ray visualization of the aorta 7. Patient has a dominant artery to the spinal cord arising from an area of stent graft coverage that is not amenable to preservation using an endovascular branch 8. Patient is currently participating in another investigational device or drug clinical trial 9. Patient is suitable, in the opinion of the investigator, for treatment in accordance with the instructions for use with a legally marketed endovascular prosthesis 10. Patient is suitable, in the opinion of the investigator, for treatment and eligible for enrollment in a manufacturer-sponsored IDE at the investigational site 11. Patient has other medical, social or psychological conditions that, in the opinion of the investigator, preclude them from receiving the pre-treatment, required treatment, and post-treatment procedures and evaluations. 12\. Patient has a freely ruptured TAAA with hemodynamic instability 13. Patient has unstable angina (defined as angina with a progressive increase in symptoms, new onset at rest or nocturnal angina, or onset of prolonged angina) 14. Patient has had a major surgical or interventional procedure unrelated to the treatment of the aneurysm planned within 30 days of the TAAA repair. Adjunctive procedures for treatment of the TAAA (i.e. carotid-subclavian bypass or iliac conduit) are acceptable. 15\. Patient has a history of an aortopathic connective tissue disease (e.g. Marfan or Ehlers Danlos syndromes) (This exclusion criteria will not apply for the BTEVAR-CTD substudy cohort) 16. Illicit drug use within the last 12 months