Aortic dissection is a life-threatening acute aortic syndrome characterized by a tear in the aortic intimal layer, which allows blood to flow into the medial layer and create a false lumen that can propagate along the aortic length. This condition can rapidly lead to fatal aortic rupture, vital organ malperfusion, or cardiac tamponade. It is universally classified by the Stanford system: Type A (involving the ascending aorta, ~60-70% of cases) and Type B (limited to the descending aorta, ~30-40% of cases).

• Etiology: Chronic hypertension is the most prevalent risk factor (present in >70% of patients), followed by connective tissue disorders (Marfan syndrome, Ehlers-Danlos syndrome), bicuspid aortic valve, aortic atherosclerosis, prior aortic surgery, traumatic aortic injury, cocaine use, and pregnancy.
• Clinical Manifestations: The hallmark symptom is sudden, severe, tearing/ripping chest or back pain. Type A dissection may be accompanied by syncope, heart failure, cardiac tamponade, myocardial infarction, or neurological deficits. Type B dissection often presents with interscapular back pain, with potential complications including lower extremity malperfusion, renal failure, or mesenteric ischemia. Untreated Type A dissection has a 1-2% hourly mortality rate, with up to 20% of patients dying before reaching the hospital.
• Diagnosis: Contrast-enhanced computed tomography angiography (CTA) is the first-line imaging modality, with >95% sensitivity and specificity to define dissection type, tear location, false lumen propagation, and organ malperfusion. Transthoracic echocardiography (TTE) is used for rapid bedside screening of Type A dissection, while transesophageal echocardiography (TEE) and magnetic resonance angiography (MRA) are used for select cases.

• Emergency Initial Stabilization: The cornerstone of all acute AD management is urgent blood pressure and heart rate control to reduce aortic wall shear stress. Targets are systolic blood pressure (SBP) of 100-120 mmHg and heart rate <60 bpm, achieved with intravenous beta-blockers (first-line), with additional vasodilators if needed. Intravenous opioids are used for pain control to reduce sympathetic activation.
• Stanford Type A Dissection: Emergency open surgical intervention is the gold standard and absolute indication, as medical management alone carries a >90% 30-day mortality rate. Procedures include ascending aortic replacement, aortic root replacement (Bentall procedure) for root involvement, and hemiarch/total arch replacement with the frozen elephant trunk technique for arch extension.
• Stanford Type B Dissection: Treatment is stratified by risk:
  • Uncomplicated Type B: Initial optimal medical therapy (OMT) with lifelong strict blood pressure control and serial surveillance is first-line.
  • Complicated Type B (malperfusion, refractory pain, high rupture risk): Thoracic Endovascular Aortic Repair (TEVAR) is the first-line minimally invasive treatment, with open surgery reserved for anatomically unsuitable cases.
• Chronic AD: Lifelong strict SBP control (<120 mmHg) is mandatory for all patients, with serial imaging surveillance. Endovascular or surgical intervention is indicated for progressive aortic dilation (>55 mm), rapid growth (>5 mm/year), or persistent symptoms.