Is a 2.5 cm aneurysm of the right common iliac artery considered large?

Assessment of a 2.5 cm Right Common Iliac Artery Aneurysm

Yes, a 2.5 cm aneurysm of the right common iliac artery is considered large and warrants intervention, as it exceeds the established threshold of 2.0 cm for iliac artery aneurysms. 1

Definition and Classification

Arterial aneurysms are defined as localized arterial dilatations ≥50% of the normal diameter. The common iliac artery has different size thresholds compared to the abdominal aorta:

• Normal common iliac artery diameter: typically <1.5 cm
• Iliac artery aneurysm threshold: ≥2.0 cm

Evidence-Based Management Recommendations

Indication for Intervention

The American College of Cardiology Foundation/American Heart Association (ACCF/AHA) guidelines clearly state that:

• Open or endovascular repair of common iliac aneurysms is indicated in patients who are good surgical candidates (Level of Evidence: A) 1
• Open repair or catheter-based intervention is indicated for visceral aneurysms measuring 2.0 cm in diameter or larger (Level of Evidence: B) 1

Treatment Options

1. Endovascular repair (EVAR):

   • Preferred for patients with suitable anatomy and reasonable life expectancy (>2 years)
   • Lower perioperative mortality and reduced cardiovascular complications
   • Requires lifelong surveillance imaging

2. Open surgical repair:

   • Reasonable for patients who cannot comply with periodic long-term surveillance required after endovascular repair
   • May be necessary for complex anatomy unsuitable for EVAR

Surveillance Recommendations

If immediate intervention is deferred (due to patient factors or preference):

• For iliac artery aneurysms, CTA is the preferred imaging modality due to their deeper location and more complex anatomy 2
• More frequent surveillance than AAA may be warranted due to the higher risk at smaller diameters

Important Considerations

• Unlike abdominal aortic aneurysms where rupture is the primary concern, peripheral artery aneurysms like iliac aneurysms carry significant risk of both rupture and thromboembolism 3
• Common iliac artery aneurysms often coexist with other aneurysms, particularly AAA, so complete vascular evaluation is recommended 1
• Patients should be assessed for risk factors that accelerate aneurysm growth (smoking, hypertension, family history)
• Medical management should include:
  • Aggressive blood pressure control
  • Statin therapy
  • Smoking cessation
  • Beta-blockers to potentially reduce aneurysm expansion rate 1, 2

Conclusion

A 2.5 cm common iliac artery aneurysm exceeds the 2.0 cm threshold for intervention established in current guidelines. Given the risks of both rupture and thromboembolism, referral to a vascular surgeon for evaluation and treatment planning is strongly indicated.