ACute Uncomplicated Type b Aortic Dissection: Endovascular Repair vs. Best Medical Therapy

Inclusion Criteria: * Aged ≥18 years, regardless of race or ethnicity; * Diagnosed with uncomplicated ABAD, i.e., a primary entry tear distal to left subclavian artery with no evidence of malperfusion, end-organ ischemia, rupture, or intractable pain, and onset of symptoms is ≤30 days prior to enrollment; * Patient has been stabilized after the acute event with control of pain and blood pressure using ≤3 intravenous antihypertensive medications; * Adequate imaging, e.g., CT with contrast (chest + abdomen+ pelvis) is available prior to enrollment; and * Indicates willingness to comply with the study protocol and is able to provide a written informed consent; * Meets criteria for inclusion in the National Death Index and Social Security Death Master File. Exclusion Criteria: * Diagnosed with Type A aortic dissection; * Evidence of complicated ABAD; * Chronic Type B aortic dissection (\>6 weeks from onset of symptoms); * Unable to be randomized and undergo treatment according to protocol within 30 days of symptom onset; * Diagnosed with traumatic dissection or penetrating ulcer; * Anatomy is not suitable for TEVAR; * Previous descending thoracic or abdominal aortic surgery (open or endovascular); * Unsuitable access sites, including infection at access sites; * Associated aortic aneurysm (descending aortic diameter ≥5.0 cm); * Life expectancy \<2 years; * Unable or unlikely to comply with BMT; * Unable or refuse to comply with follow-up; * Intend to participate in another trial within 3 months of enrollment; * Pregnant or breast-feeding; * Vasculitis or known genetic connective tissue disorder (Marfan's syndrome or Ehlers-Danlos syndrome) * Active systemic infection; * Chronic kidney disease stage 3-5 (estimated glomerular filtration rate \<60 mL/min/1.73m2); * Cerebral vascular accident within past 3 months; or * Clinically significant gastrointestinal bleeding, major surgery, myocardial infarction, or untreated coagulopathy within past 6 weeks.