The purpose of the study is to conduct a randomized controlled trial comparing best medical therapy (BMT) alone to BMT with thoracic endovascular aortic repair (BMT+TEVAR) for uncomplicated acute type B aortic dissection.

Study Design:

This is a prospective, two-arm, parallel-group, single-center, pragmatic, randomized clinical trial.

Population:

The target population comprises all adult patients aged 18 years and older who present with uncomplicated acute type B aortic dissection. The study sample will include 436 subjects of both genders and any race or ethnicity.

Procedures:

Eligible and consented patients will be enrolled into the study if all eligibility criteria are met and will be randomly allocated to one of the two study arms: BMT vs BMT+TEVAR

Study Duration:

The study is expected to accrue patients over the course of 5 years and total follow up per patient for 5 years. Overall duration of the study is anticipated to be about 10 years for completion of all study endpoints.

Endpoints:

• Primary Outcome: To determine all-cause mortality among both study arms.
• Secondary Outcomes: To assess any major morbidity events (rupture, aortic intervention or reintervention, progression to complicated dissection, aneurysm formation, malperfusion resulting in organ failure, and aorta-specific mortality), as will quality of life measures, temporal discounting assessment and outcomes comparison in an observational cohort of patients who decline to be randomized due to a strong treatment preference.

Risks and Benefits:

Since this study involves only usual care and FDA-approved treatments, the investigators do not expect any additional physical risks to patients beyond those associated with usual care. One discernible risk involved in study participants is an unintentional disclosure of sensitive patient health information.

The participants of this study do not stand to benefit directly from taking part. However, the investigators hope that the results obtained from this study would provide useful information that would help delineate a standard and economical management protocol for acute Type B aortic dissection in future.

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.

Deidentified data will be made available following IRB approval

Participant and investigator/treating physician would be blinded until the day of treament initiation