Safety and Efficacy of Endovascular Repair of Complex Aortic Pathology With Physician-modified Endovascular Grafts (PMEGs)

INCLUSION CRITERIA: General inclusion criteria (applicable to all 3 study arms): * Aortic pathology that fits one of the study arms (see below for detailed description) * Aortic pathology that cannot be treated within the Instructions for Use of an FDA- approved, commercially-available device * Aortic aneurysm that can be treated within the Instructions for Use of an FDA-approved, commercially-available custom-manufactured device but deemed unsafe to wait the required time for device manufacturing * Subject is at high-risk of morbidity and mortality with open surgical repair based on cardiopulmonary function, extent of comorbid disease, and anatomic complexity * Iliac and/or femoral access vessel morphology that is compatible with vascular access techniques, devices, or accessories, with or without use of a surgical or endovascular conduit * Non-aneurysmal aortic segment proximal to the aortic pathology with a: * Minimum neck length of 20 mm * Diameter between 20 - 42 mm * Non-aneurysmal aortic or iliac segment distal to the aortic pathology with: * Aortic distal fixation site greater than 20 mm in length and diameter between 20-42 mm * Iliac artery distal fixation site greater than 10 mm in length and diameter range 8- 25 mm * Age ≥21 years old * Life expectancy: ≥2 years Arm1: * Complex abdominal aortic aneurysm, specifically juxtarenal or suprarenal abdominal aortic aneurysm or type IV thoracoabdominal aortic aneurysm, with maximum diameter of ≥5.5 cm for men or ≥5.0 cm for women, growth ≥0.5 cm in 6 months, or concomitant iliac aneurysm ≥3 cm * Prior endovascular aortic aneurysm repair with loss of proximal seal requiring incorporation of the renal arteries, SMA, and/or CA for repair, without aneurysmal disease extending above the diaphragmatic hiatus * Prior open abdominal aortic aneurysm repair with aneurysmal disease proximal to the repair requiring incorporation of the renal arteries, SMA, and/or CA for repair, without aneurysmal disease above the diaphragmatic hiatus * Saccular complex abdominal aortic aneurysm deemed at significant risk for rupture * Symptomatic complex aortic aneurysm * Penetrating aortic ulcer with depth ≥1 cm or width ≥2 cm, for which endovascular repair requires incorporation of the renal arteries, SMA, and/or CA, without involvement of the aorta above the diaphragmatic hiatus * Aortic pseudoaneurysm for which endovascular repair requires incorporation of the renal arteries, SMA, and/or CA, without involvement of the aorta above the diaphragmatic hiatus Arm2: * Type I, II, or III thoracoabdominal aortic aneurysm with maximum diameter of ≥5.5 cm, or growth ≥0.5 cm in 6 months * Prior endovascular aortic aneurysm repair with loss of proximal seal requiring incorporation of the renal arteries, SMA, and/or CA for repair with aneurysmal disease extending above the diaphragmatic hiatus * Prior thoracic endovascular aneurysm repair with loss of distal seal requiring incorporation of the renal arteries, SMA, and/or CA for repair * Prior open abdominal aortic aneurysm repair with aneurysmal disease proximal to the repair requiring incorporation of the renal arteries, SMA, and/or CA for repair, with aneurysmal disease above the diaphragmatic hiatus * Saccular type I, II, or III thoracoabdominal aortic aneurysm deemed at significant risk for rupture * Symptomatic type I, II, or III thoracoabdominal aortic aneurysm * Penetrating aortic ulcer with depth ≥1 cm or width ≥2 cm, for which endovascular repair requires incorporation of the renal arteries, SMA, and/or CA, with involvement of the aorta above the diaphragmatic hiatus * Aortic pseudoaneurysm for which endovascular repair requires incorporation of the renal arteries, SMA, and/or CA, with involvement of the aorta above the diaphragmatic hiatus Arm 3: * Acute or chronic type B aortic dissection with indication for repair including, but not limited to renal, mesenteric, or lower extremity malperfusion, progression of dissection, or persistence of symptoms despite optimal medical therapy * Prior repair of type A dissection and development of acute or chronic type B dissection component with indication for repair (listed above) * Aortic intramural hematoma (IMH) with indication for repair including, but not limited to renal, mesenteric, or lower extremity malperfusion, progression of dissection, or more typically, persistence of symptoms despite optimal medical therapy Arm 4 * Patient does not meet the inclusion/exclusion criteria of Arms 1 - 3 * Patient has prohibitive operative risk for open repair and no other viable endovascular treatment option * Estimated perioperative risk is lower than the estimated 1-year mortality without surgery EXCLUSION CRITERIA: General Exclusion Criteria * Subject is eligible for enrollment in a manufacturer-sponsored IDE at the investigational site * Subject is unwilling to comply with the follow-up schedule * Inability or refusal to give informed consent by subject or legal representative * Subject is pregnant or breastfeeding * Subject has a ruptured aneurysm Arm 5 • Patient meets criteria for Arms 1-4 \- Patient is undergoing repair using the TREO bifurcated stent graft Indications for using TREO bifurcated stent graft: * Patient has undergone a prior endovascular aortic repair and meets criteria for repair; OR * -Patient has measured length from the lowest renal artery to the aortic bifurcation (either de novo or from a prior endograft) \< 115 mm; OR * In patients with notable vessel tortuosity, where centerline measurement may not accurately reflect the distance covered needed in situ; OR * Additional clinical or anatomic scenarios where forthcoming experience may demonstrate the TREO endograft to be superior to the currently-used Alpha/Alpha 2 endograft. Medical Exclusion Criteria * Known sensitivities or allergies to the materials of construction of the devices * Known hypersensitivity or contraindication to anticoagulation or contrast media that