What is the first line treatment for type B aortic dissection?

First-Line Treatment for Type B Aortic Dissection

Medical therapy including pain relief and blood pressure control is the first-line treatment for all patients with acute type B aortic dissection (TBAD). 1

Initial Management Algorithm

For All Type B Aortic Dissections:

• Immediate medical therapy should be initiated with:
  • Pain control to achieve hemodynamic targets 1
  • Blood pressure control with target systolic BP <120 mmHg and heart rate <60 bpm to reduce aortic wall stress 1
  • Beta-blockers should be considered as first-line antihypertensive therapy 1, 2
    • Options include esmolol (short-acting IV beta-blocker), metoprolol, or labetalol 1, 3
    • For severe hypertension, beta-blockers can be combined with vasodilating agents like nitroprusside or clevidipine 1

Assessment for Complications:

• Evaluate for signs of complicated TBAD 1:
  • Aortic rupture/tamponade
  • Cerebral malperfusion/stroke
  • Mesenteric malperfusion
  • Lower extremity malperfusion
  • Refractory pain despite medical therapy
  • Rapidly expanding aortic diameter

Treatment Based on Presentation

Uncomplicated Type B Aortic Dissection:

• Continue medical therapy with close surveillance 1
• Follow-up imaging at 1,3,6, and 12 months after onset, then yearly if stable 1
• Consider TEVAR in the subacute phase (between 14-90 days) for patients with high-risk features 1:
  • Primary entry tear >10 mm located at inner aortic curvature
  • Initial aortic diameter >40 mm
  • Initial false lumen diameter >20 mm
  • Partial false lumen thrombosis 1

Complicated Type B Aortic Dissection:

• Emergency intervention is recommended 1
• TEVAR (Thoracic Endovascular Aortic Repair) is the first-line therapy for complicated cases 1, 4
• If malperfusion persists after TEVAR, consider:
  • Angiographic control
  • Percutaneous malperfusion repair
  • Extra-anatomic bypass for persistent lower extremity malperfusion 1

Long-term Management

• Lifelong antihypertensive therapy is recommended for all patients 1, 2
• For chronic TBAD with descending thoracic aortic diameter ≥60 mm, intervention is recommended in patients at reasonable surgical risk 1
• For chronic TBAD with descending thoracic aortic diameter ≥55 mm, intervention should be considered in patients with low procedural risk 1

Important Considerations and Pitfalls

• Avoid excessive blood pressure reduction that could compromise organ perfusion 5
• Monitor for hemodynamic instability during intensive blood pressure control, especially with high-dose continuous infusion labetalol 3
• Regular imaging surveillance is critical to detect aortic expansion or other complications early 1, 4
• In pregnant patients with TBAD, strict control of the pregnant patient and fetus with conservative medical management is recommended 1

By following this algorithm, patients with type B aortic dissection can receive appropriate initial management based on their clinical presentation, with the goal of preventing aortic rupture, propagation of the dissection, and end-organ malperfusion.