What is the management of type B aortic dissection?

Management of Type B Aortic Dissection

Immediate Medical Management (All Patients)

All patients with type B aortic dissection require immediate medical therapy with aggressive blood pressure and heart rate control as the foundation of treatment, regardless of whether they have complicated or uncomplicated disease. 1

Hemodynamic Targets and Monitoring

• Target systolic blood pressure <120 mmHg and heart rate ≤60 beats per minute to reduce aortic wall stress 1, 2
• Establish invasive arterial line monitoring and continuous three-lead ECG recording 1
• Admit to intensive care unit for close surveillance 1
• Exception: In cases of spinal ischemia or concomitant brain injury, maintain higher mean arterial pressure to preserve organ perfusion 1

First-Line Pharmacologic Therapy

• Intravenous beta-blockers (e.g., labetalol) are the recommended first-line agents 1, 2
• If beta-blockers alone are insufficient, add intravenous vasodilators such as dihydropyridine calcium channel blockers or nitrates 1
• Provide adequate pain control to achieve hemodynamic targets 1
• After 24 hours, switch to oral beta-blockers if gastrointestinal transit is preserved and hemodynamic targets are achieved 1

Risk Stratification: Complicated vs Uncomplicated

Complicated Type B Dissection (Emergency Intervention Required)

Emergency intervention is recommended for complicated acute type B aortic dissection, with TEVAR as the first-line therapy. 1, 2

Complicated dissection is defined by:

• Aortic rupture or impending rupture 2
• Malperfusion syndromes (cerebral, mesenteric, renal, or lower extremity) 1, 2
• Intractable pain despite medical therapy 1, 2
• Rapidly expanding aortic diameter 1, 2
• Periaortic or mediastinal hematoma 1

Uncomplicated Type B Dissection (Medical Management)

Continue medical therapy with close surveillance for uncomplicated type B aortic dissection. 1, 2

• Maintain strict antihypertensive therapy with beta-blockers as preferred agents 1
• Perform follow-up imaging at 1,3,6, and 12 months after onset, then yearly if stable 2
• Consider TEVAR in the subacute phase for high-risk features including: primary entry tear >10 mm, initial aortic diameter >40 mm, initial false lumen diameter >20 mm, or partial false lumen thrombosis 2

Chronic Type B Dissection Management

Long-Term Medical Therapy

• Lifelong antihypertensive therapy is mandatory for all patients to prevent aortic expansion and reduce complications 2
• Target blood pressure <135/80 mmHg 1
• Beta-blocking agents are preferred, with combination therapy typically needed 1

Indications for Intervention in Chronic Phase

In chronic type B aortic dissection with descending thoracic aortic diameter ≥60 mm, treatment is recommended in patients at reasonable surgical risk. 1, 2

Additional indications for intervention:

• Acute symptoms of malperfusion, rupture, or disease progression 1
• Progressive aortic enlargement to 6.0 cm with symptoms 1
• Endovascular stenting is recommended if surgical indication exists and anatomy is suitable 1

Surveillance Strategy

• MRI is the preferred imaging modality for serial follow-up, avoiding ionizing radiation and nephrotoxic contrast agents 1
• Document studies on prints rather than video to facilitate comparison of progressive enlargement 1
• Monitor for false lumen expansion, aneurysm formation, or signs of impending rupture 3, 4

Common Pitfalls and Caveats

• Do not delay intervention in complicated dissections: Emergency TEVAR should be performed immediately when malperfusion or rupture is present 1
• Avoid vasodilators without prior beta-blockade: This can cause reflex tachycardia and increased aortic wall stress 5
• Monitor for hemodynamic instability with continuous infusion beta-blockers: Hypotension requiring fluid boluses or therapy discontinuation can occur in up to 50% of patients receiving high-dose continuous labetalol 6
• Recognize that uncomplicated dissections can deteriorate: Close surveillance is essential as approximately 20-40% may develop complications requiring intervention during follow-up 3, 4