What is the management for a 2.3 cm iliac artery aneurysm?

Management of a 2.3 cm Iliac Artery Aneurysm

For a 2.3 cm iliac artery aneurysm, surveillance with regular imaging is recommended rather than immediate intervention, as repair is typically indicated when the aneurysm reaches ≥3.5 cm in diameter. 1

Surveillance Approach

Initial Assessment

• Determine the exact location (common, internal, or external iliac artery)
• Evaluate for symptoms (most 2.3 cm aneurysms are asymptomatic)
• Screen for other aneurysms, particularly:
  • Contralateral iliac artery aneurysms
  • Abdominal aortic aneurysm (AAA)
  • Femoral or popliteal aneurysms 1

Imaging Protocol

• Initial baseline imaging (CT angiography preferred)
• Follow-up imaging at:
  • 6-12 months after initial diagnosis
  • Annually thereafter if stable
  • More frequent imaging if growth rate accelerates (>5mm in 6 months) 2

Medical Management

• Blood pressure control (target <130/80 mmHg)
• Beta-blockers may be considered to reduce aneurysm expansion rate 1
• Lipid management (statin therapy)
• Antiplatelet therapy
• Smoking cessation if applicable 2

Indications for Intervention

Intervention is recommended when:

1. Aneurysm diameter reaches ≥3.5 cm 1
2. Rapid growth occurs (>5mm in 6 months)
3. Patient becomes symptomatic (pain, compression of adjacent structures)
4. Evidence of distal embolization is present
5. Progression of aneurysm is noted 2

Rationale for Size Threshold

The 3.5 cm threshold for repair is based on risk-benefit analysis:

• Rupture of iliac aneurysms <3.5 cm is rare 1
• The Dutch Surgical Aneurysm Audit found median diameter at elective repair was 4.3 cm, while ruptured aneurysms had a median diameter of 6.8 cm 1
• Smaller aneurysms (2-2.5 cm) have been observed without enlargement for mean follow-up periods of 57 months 3

Intervention Options When Indicated

When intervention becomes necessary:

1. Open surgical repair: Traditional approach with excellent long-term durability

   • Particularly appropriate for younger, healthier patients
   • Recommended for patients who cannot comply with long-term surveillance after endovascular repair 1

2. Endovascular repair: Less invasive option

   • Stent-graft placement
   • Preservation of at least one hypogastric artery is crucial to prevent pelvic ischemia 1
   • Requires lifelong surveillance imaging

Special Considerations

• If concomitant AAA is present, repair both when iliac aneurysm reaches ≥3.5 cm, even if AAA is small 1
• Risk of complications from hypogastric artery exclusion:
  • Buttock claudication (27% with unilateral exclusion)
  • Erectile dysfunction (10% in men)
  • Rare but serious: bowel ischemia, spinal ischemia (<1%) 2

Prognosis

With appropriate surveillance and timely intervention when indicated, the prognosis for patients with small iliac artery aneurysms is excellent. The key is adherence to the surveillance protocol to identify growth that would warrant intervention before complications occur.