What is the recommended treatment approach for patients with thoracic aortic disease using Thoracic Endovascular Aortic Repair (TEVAR)?

Thoracic Endovascular Aortic Repair (TEVAR) for Thoracic Aortic Disease

TEVAR is the recommended first-line therapy for complicated acute type B aortic dissection and is recommended over open repair for unruptured descending thoracic aortic aneurysms when anatomy is suitable. 1

Indications for TEVAR

Type B Aortic Dissection

• Complicated acute Type B aortic dissection:

  • TEVAR is the first-line therapy 1
  • Complications include: persistent/recurrent pain, uncontrolled hypertension, early aortic expansion, malperfusion, and signs of rupture 1
  • Emergency intervention is recommended in these cases 1

• Uncomplicated acute Type B aortic dissection:

  • Initial management is medical therapy with pain relief and blood pressure control 1
  • TEVAR should be considered in the subacute phase (14-90 days) for selected patients with high-risk features 1
  • High-risk features include: primary entry tear >10mm at inner aortic curvature, initial aortic diameter >40mm, initial false lumen diameter >20mm 1

• Chronic Type B aortic dissection:

  • TEVAR is indicated when diameter reaches ≥60mm in patients at reasonable surgical risk 1
  • Consider intervention at ≥55mm in patients with low procedural risk 1
  • Emergency intervention for rupture, malperfusion, or disease progression 1

Thoracic Aortic Aneurysms

• Descending thoracic aortic aneurysms (DTA):
  • TEVAR is recommended over open repair when anatomy is suitable and diameter ≥55mm 1, 2, 3
  • Lower thresholds may apply for women, patients with connective tissue disorders, and rapid growth (≥10mm/year) 2

Other Indications

• Intramural hematoma (IMH):

  • Complicated type B IMH: TEVAR is recommended 1
  • Uncomplicated type B IMH: Initial medical therapy with careful surveillance 1

• Penetrating atherosclerotic ulcer (PAU):

  • Complicated type B PAU: TEVAR is recommended 1
  • Uncomplicated type B PAU with high-risk imaging features: TEVAR should be considered 1

• Traumatic aortic injury:

  • Severe aortic injury (grade 4): Immediate TEVAR is recommended over open surgery 1
  • Moderate aortic injury (grade 3): TEVAR is recommended 1

Technical Considerations

Preoperative Planning

• Fine-cut (≤0.25mm) CTA of the entire aorta plus iliac and femoral arteries is essential 3
• Three-dimensional centerline reconstruction software is recommended for accurate planning 3
• Assess proximal and distal landing zones (minimum 2cm of healthy aorta, diameter <40mm) 2
• Evaluate left subclavian artery (LSA) involvement and vertebral artery anatomy 3

Procedural Considerations

• Stent-graft sizing:

  • 10-15% oversizing for aneurysms 2
  • Minimal to no oversizing for type B dissections to prevent complications 2

• Left subclavian artery management:

  • Revascularize LSA before TEVAR if coverage is planned to reduce risk of spinal cord ischemia and stroke 1, 2

• Spinal cord protection:

  • Consider cerebrospinal fluid drainage in high-risk patients 2
  • Avoid covering vessels supplying major spinal cord segments in elective settings 2

Postoperative Care

• Follow-up imaging:
  • After TEVAR for acute aortic syndrome: Imaging at 1,6, and 12 months, then yearly until the fifth post-operative year 1
  • For medically treated type B aortic dissection or IMH: Imaging at 1,3,6, and 12 months after onset, then yearly if stable 1
  • For medically treated PAU: Imaging at 1 month after diagnosis, then every 6 months if stable 1

Complications and Management

Major Complications

• Endoleaks: Particularly types I and III require re-intervention 1, 2
• Spinal cord ischemia: Incidence around 5%, similar between endovascular and open repair 1
• Stroke: More common with arch involvement 2
• Device migration: Requires careful surveillance 2
• Access site complications: More common with larger delivery systems 2

Outcomes

• TEVAR shows better early results than conventional therapy for complicated type B aortic dissection 4
• TEVAR is associated with lower morbidity and mortality compared to open repair, especially in rupture cases 3, 5
• Five-year freedom from aortic reintervention or rupture is approximately 80% for both TEVAR and open repair 6
• TEVAR promotes thrombosis of the false lumen and may prevent aortic enlargement in long-term follow-up 4

Pitfalls and Caveats

• Excessive oversizing can lead to retrograde dissection, particularly in acute dissection cases
• TEVAR is not recommended for patients with heritable thoracic aortic disease (e.g., Marfan syndrome) as first-line therapy
• Emergency repair of ruptured thoracic aorta still shows high rates of perioperative mortality and morbidity despite endovascular approach 5
• Long-term durability remains uncertain compared to open repair, necessitating lifelong surveillance 7
• Accurate endograft sizing is vital; measuring the thoracic aorta based on admission CT may be imprecise due to fluctuations in aorta diameter from hemorrhagic shock and resuscitation 1

TEVAR has revolutionized the treatment of thoracic aortic disease with improved outcomes compared to open repair, but patient selection, anatomical considerations, and long-term surveillance remain critical for success.