What is the recommended treatment approach for patients with abdominal aortic aneurysms using Endovascular Aneurysm Repair (EVAR)?

Endovascular Aneurysm Repair (EVAR) for Abdominal Aortic Aneurysms

In patients with abdominal aortic aneurysms (AAA) with suitable anatomy and reasonable life expectancy (>2 years), EVAR should be considered as the preferred therapy over open repair due to significantly lower perioperative mortality and morbidity. 1

Indications for AAA Repair

Size-based Criteria

• Elective repair is recommended when:
  • AAA diameter ≥55 mm in men 1
  • AAA diameter ≥50 mm in women 1
  • Saccular aneurysm ≥45 mm (may be considered) 1
  • Growth rate ≥5 mm in 6 months or ≥10 mm per year (may be considered) 1

Patient Selection

• EVAR is particularly beneficial for:

  • Patients with high perioperative risk due to cardiopulmonary or renal comorbidities 1
  • Ruptured AAA with suitable anatomy (reduces perioperative morbidity and mortality) 1

• EVAR is contraindicated in:

  • Patients with limited life expectancy (<2 years) 1
  • Patients who cannot comply with lifelong surveillance requirements 1

Preoperative Evaluation

Imaging Assessment

1. CCT (Computed Tomography) is the optimal pre-operative imaging modality 1

   • Provides complete vascular evaluation of entire aorta
   • Allows assessment of aneurysm morphology and calcification
   • Essential for sizing the aorto-iliac system

2. Alternative imaging if CCT contraindicated:

   • CMR (Cardiovascular Magnetic Resonance), though calcification assessment is challenging 1

3. Additional assessments:

   • DUS (Duplex Ultrasound) of femoro-popliteal segment to detect concomitant aneurysms 1

Cardiac Evaluation

• Pre-operative cardiac evaluation is critical due to cardiovascular risk 1
• Important: Routine coronary angiography and systematic revascularization in patients with chronic coronary syndromes is NOT recommended 1

Technical Considerations

Access Approach

• Percutaneous femoral approach is preferred 1
  • Provides quick access
  • Reduced invasiveness
  • Allows local anesthesia
  • Ultrasound-guided access reduces complications and shortens operation time

Device Selection

• Adherence to manufacturer's instructions for use is essential 1
• Current devices offer:
  • Active fixation
  • Repositioning ability
  • Low-profile design
  • Polymer-filled rings for improved sealing 1

Complex Cases

• For juxta- or para-renal AAA, fenestrated or branch stent endografts should be considered 1
• Treatment at high-volume centers is recommended for complex cases 1

Postoperative Surveillance

Follow-up Protocol

• Lifelong surveillance is mandatory due to risk of late complications 1
• Initial imaging at 30 days post-EVAR (CCT + DUS/CEUS) 1
• Follow-up at 1 and 12 months post-operatively 1
• Annual surveillance thereafter if no abnormalities are found 1
• DUS/CEUS annually with CCT or CMR every 5 years 1

Complications to Monitor

• Endoleaks (most common complication, up to 1/3 of cases) 1
  • Type I and III require immediate correction
  • Type II may seal spontaneously but requires monitoring
• Device migration
• Aneurysm sac expansion
• Risk of rupture

Outcomes and Considerations

Benefits of EVAR vs. Open Repair

• Lower perioperative mortality (<1% vs. 4-5%) 1
• Reduced cardiovascular complications 1
• Shorter hospital stay and ICU utilization 2
• Potentially lower costs in high-risk patients 2

Long-term Considerations

• Higher risk of re-intervention compared to open repair 1, 3
• Similar long-term mortality compared to open repair 1
• Quality of life benefits in high-risk patients 2

Common Pitfalls and Caveats

1. Failure to adhere to manufacturer's instructions can lead to device failure and complications 1

2. Inadequate surveillance can result in missed endoleaks and late rupture 1

3. Chronic anticoagulation increases risk of re-intervention, late conversion surgery, and mortality 1

4. Underestimating neck morphology - the proximal neck is critical for successful EVAR 1

5. Patient selection errors - offering EVAR to patients with unsuitable anatomy or very limited life expectancy 1

EVAR has transformed AAA management by providing a less invasive alternative with lower perioperative risks, particularly beneficial for higher-risk patients who might not tolerate open repair. However, the need for lifelong surveillance and potential for late complications must be carefully considered in the decision-making process.