Iliac Aneurysms

• • Occur with abdominal aortic aneurysms (AAA) in 20%

  • Natural history of these aneurysms unknown

  • Rupture occurs frequently but believed to be rare in aneurysms < 3 cm

  • -Size most important determinant of rupture risk

Epidemiology

• • Isolated iliac aneurysms rare

  • Occurs in < 1% of population over age 50

  • Solitary iliac aneurysms of common iliac artery, 70% of cases; of internal iliac, 20% of cases; of external iliac, 10% of cases

Symptoms and Signs

• • 50% of patients are symptomatic

  • -Compression or erosion into surrounding structures

    -Rupture

  • Sepsis from ureteral obstruction causing pyelonephritis

  • Erosion or rupture into ureter or bladder can cause hematuria, possibly massive

  • Neurologic symptoms

  • -Compression of femoral, obturator, sciatic nerves

  • Massive leg swelling

  • -Rupture of iliac artery into iliac vein causing AV fistula

  • Most symptomatic iliac aneurysms palpable on abdominal or rectal exam

  • Perianal ecchymosis and decreased sphincter tone seen in cases of rupture

Imaging Findings

• • US, CT scan, MRI, arteriography can diagnose

  • US depth of arteries in pelvis, overlying intestinal gas may limit study

  • CT scan and MRI excellent

  • Arteriography may look normal because of mural thrombus; done to evaluate pelvic circulation prior to repair

• • Evaluate for other sites of peripheral aneurysms

• • CT scan and MRI

  • Arteriography

• • Solitary aneurysms:

  • -Retroperitoneal approach

    -Hypogastric artery can be safely ligated if contralateral artery is normal

    -If ipsilateral hypogastric aneurysmal, open saci and ligate branches

  • Bilateral common iliac artery aneurysm:

  • -Bifurcated interposition graft

  • Many treated with endovascular repair

Surgery

Indications

• • Iliac aneurysms > 3 cm with good operative risk, consider repair

References