What is the management of thoracic aorta aneurysmal dilatation and aortic dissection?

Management of Thoracic Aortic Aneurysmal Dilatation and Aortic Dissection

Surgical intervention is recommended for thoracic aortic aneurysms when the diameter reaches ≥55 mm in patients with tricuspid aortic valve, ≥50 mm in women with abdominal aortic aneurysms, and ≥60 mm for unruptured descending thoracic aortic aneurysms. 1

Thoracic Aortic Aneurysm Management

Surveillance

• Initial Evaluation:

  • Transthoracic echocardiography (TTE) to assess aortic valve anatomy, function, and aortic root/ascending aorta diameters 1
  • CT or MRI to confirm TTE measurements, rule out aortic asymmetry, and establish baseline diameters 1

• Follow-up Imaging Schedule:

  • For aortic root diameter <45 mm without risk factors: Annual TTE 1
  • For aortic root diameter <45 mm with risk factors: Every 6 months 1
  • For aortic root diameter ≥45 mm without risk factors: Every 6-12 months 1
  • For thoracoabdominal aorta: CMR or CCT every 3-5 years if stable 1

Surgical Intervention Thresholds

• Ascending aorta/aortic root with tricuspid valve: ≥55 mm 1
• Descending thoracic aorta (DTA): ≥55 mm 1
• Thoracoabdominal aortic aneurysm (TAAA): ≥60 mm 1
• Abdominal aortic aneurysm (AAA): ≥55 mm in men, ≥50 mm in women 1
• Lower thresholds for patients with:
  • Heritable thoracic aortic disease (HTAD)
  • Rapid growth (>0.5 cm/year)
  • Family history of dissection
  • Symptoms attributable to the aneurysm

Medical Management

• Blood pressure control is essential for all patients with aortic aneurysms 1, 2
• Beta-blockers are first-line therapy to reduce heart rate and blood pressure 2
• Target: Heart rate ≤60 bpm and systolic BP between 100-120 mmHg 2
• Additional agents if needed:
  • Non-dihydropyridine calcium channel blockers (if beta-blockers contraindicated)
  • ACE inhibitors or ARBs for additional BP control

Aortic Dissection Management

Classification and Initial Approach

• Type A (involving ascending aorta): Immediate surgical intervention 1, 2
• Type B (distal to left subclavian artery):
  • Uncomplicated: Medical management initially 1, 2
  • Complicated: Emergency intervention, preferably TEVAR 1, 2

Type A Dissection Management

1. Emergency surgical repair including:

   • Resection of aneurysmal aorta and proximal extent of dissection 1
   • Aortic valve resuspension if possible 1
   • Open distal anastomosis to improve survival and increase false lumen thrombosis 1
   • Consider hemi-arch repair unless arch has intimal tear or significant aneurysm 1

2. For malperfusion syndromes:

   • Immediate aortic surgery for cerebral, mesenteric, lower limb, or renal malperfusion 1
   • Consider invasive angiographic diagnostics for mesenteric malperfusion 1

Type B Dissection Management

1. Uncomplicated Type B:

   • Initial medical therapy with aggressive BP control 1, 2
   • Consider TEVAR in subacute phase (14-90 days) for high-risk features 1
   • High-risk features include: large false lumen, partial false lumen thrombosis, large entry tear

2. Complicated Type B:

   • TEVAR is recommended as first-line therapy 1, 2
   • Complications requiring intervention:
     • Malperfusion syndromes
     • Rupture or impending rupture
     • Refractory pain
     • Refractory hypertension
     • Rapid aortic expansion

3. Chronic Type B:

   • Intervention recommended when descending thoracic aortic diameter ≥60 mm 1
   • Consider intervention at ≥55 mm in low-risk patients 1

Penetrating Atherosclerotic Ulcer (PAU) and Intramural Hematoma (IMH)

• Type A PAU/IMH: Surgical repair recommended 1
• Type B PAU/IMH: Initial medical therapy under surveillance 1
• Complicated Type B PAU/IMH: TEVAR recommended 1
• Uncomplicated Type B PAU with high-risk features: Consider TEVAR 1

Follow-up After Treatment

Medical Management Follow-up

• Type B dissection or IMH: Imaging at 1,3,6, and 12 months, then yearly if stable 1, 2
• PAU: Imaging at 1 month, then every 6 months if stable 1, 2

Post-TEVAR Follow-up

• Imaging at 1,6, and 12 months, then yearly until the fifth post-operative year 1

Post-Open Surgery Follow-up

• CCT and TTE within 6 months, then CCT at 12 months and yearly if stable 1, 2
• If no complications within 5 years, consider CCT every 2 years thereafter 1

Special Considerations

Genetic Testing and Family Screening

• Gather family history for three generations about thoracic aortic disease 1
• Genetic counseling and testing for patients with risk factors for heritable thoracic aortic disease 1
• Cascade testing of at-risk biological relatives if pathogenic variant identified 1
• TTE screening of first-degree relatives if no pathogenic variant identified 1

Pitfalls to Avoid

1. Delayed diagnosis - Classic triad of sudden chest pain, pulse deficit, and aortic regurgitation is often absent
2. Inadequate blood pressure control - Failure to achieve target BP increases risk of aneurysm growth and dissection
3. Inappropriate imaging modality - TTE is inadequate for surveillance of distal ascending aorta, arch, or descending thoracic aorta 1
4. Insufficient follow-up - Aneurysmal degeneration after dissection occurs in approximately 50% of patients by 5 years 3
5. Overlooking familial patterns - 21% of thoracic aortic aneurysm patients have first-order relatives with arterial aneurysms 4

By following these evidence-based guidelines for management of thoracic aortic aneurysms and dissections, clinicians can optimize outcomes and reduce mortality for these potentially devastating conditions.