What is the recommended treatment for common iliac artery aneurysms?

Treatment of Common Iliac Artery Aneurysms

Elective repair is recommended for common iliac artery aneurysms ≥3.5 cm in diameter to prevent rupture and associated morbidity and mortality. 1, 2

Diagnosis and Surveillance

• Common iliac artery aneurysms frequently coexist with abdominal aortic aneurysms (20-40% of cases) and should be evaluated with appropriate imaging 2, 3
• For common iliac artery aneurysms measuring 2.0-2.9 cm, surveillance with ultrasound every 12 months is recommended 3
• For aneurysms measuring 3.0-3.4 cm, surveillance should be increased to every 6 months 3
• CT angiography is recommended when the aneurysm approaches intervention threshold (≥3.5 cm) or for pre-intervention planning 3

Indications for Intervention

• Repair is indicated for common iliac artery aneurysms ≥3.5 cm in diameter 1, 2
• Symptomatic aneurysms warrant immediate repair regardless of size 1, 2
• The risk of rupture increases significantly with size, with no documented ruptures below 3.8 cm in clinical studies 4
• Median expansion rate is approximately 0.29 cm/year, with hypertension predicting faster expansion 4

Treatment Options

Endovascular Repair

• Endovascular repair is indicated as first-line treatment for most anatomically suitable patients 2, 4
• Benefits include lower perioperative complications and shorter hospital stays compared to open repair 4
• Requires long-term surveillance imaging to monitor for endoleaks and aneurysm sac stability 1, 2
• CT imaging is recommended at 1 month and 12 months post-procedure, and annually thereafter if stable 2

Open Surgical Repair

• Open repair is indicated for patients who are good surgical candidates but cannot comply with the long-term surveillance required after endovascular repair 1, 2
• Open repair may be preferred for patients with compressive symptoms or arteriovenous fistulas 4
• Perioperative mortality is similar to endovascular repair for elective cases (approximately 1%) but higher for emergency cases (26%) 4

Technical Considerations

• When treating iliac aneurysms, preservation of at least one hypogastric (internal iliac) artery is crucial to decrease the risk of pelvic ischemia 1, 2
• Exclusion of internal iliac arteries can lead to significant complications, including buttock claudication (27% with unilateral exclusion, 36% with bilateral exclusion) 2
• For patients with anatomical challenges, hybrid approaches combining endovascular and open techniques may be necessary 5, 6
• Endovascular techniques may include aorto-uni-iliac endografts with femoro-femoral bypass, or bell-bottom techniques for aneurysms at the iliac bifurcation 7

Post-Intervention Management

• Beta-adrenergic blocking agents may be considered to reduce the rate of aneurysm expansion 1, 2
• Smoking cessation is strongly advised for all patients with aneurysms 2
• After endovascular repair, periodic long-term surveillance imaging is mandatory to monitor for complications 1, 2
• At 3 years, secondary patency rates are excellent for both open and endovascular repair (99.6% vs 100%) 4

Pitfalls and Caveats

• Isolated common iliac artery aneurysms are rare but can be difficult to diagnose due to their deep pelvic location 6
• When treating common iliac aneurysms with concomitant abdominal aortic aneurysms, repair of both is recommended 1
• Patients with femoral or popliteal aneurysms should be evaluated for concomitant iliac and aortic aneurysms 1
• The risk of developing aortic aneurysms after isolated iliac aneurysm repair should be considered in long-term follow-up 8