What is the treatment for a pelvic vessel aneurysm?

Treatment of Pelvic Vessel Aneurysm

For pelvic vessel aneurysms (specifically iliac artery aneurysms), elective repair is recommended when the common iliac artery diameter reaches ≥3.5 cm, with preservation of at least one internal iliac artery (hypogastric artery) being critical to prevent devastating pelvic ischemia complications. 1

Size-Based Treatment Thresholds

• Common iliac artery aneurysms ≥3.5 cm require elective repair to balance procedural risks against rupture risk, as rupture at diameters <4 cm is rare in large case series 1
• Aneurysms measuring <3.5 cm can be monitored with annual ultrasound surveillance, as rupture risk remains low at smaller diameters 1
• The median diameter of ruptured iliac aneurysms at presentation is 6.8 cm, while elective repairs are typically performed at 4.3 cm 1

Critical Anatomic Consideration: Internal Iliac Artery Preservation

Preservation of at least one hypogastric (internal iliac) artery is mandatory when anatomically feasible to prevent severe pelvic ischemia complications 1. The consequences of bilateral internal iliac artery exclusion include:

• Buttock claudication occurs in 27% with unilateral exclusion and 36% with bilateral exclusion 1
• Bowel ischemia requiring colectomy, with perioperative mortality rates up to 50% in affected patients 2
• Spinal cord ischemia resulting in permanent paraplegia 2
• Gluteal compartment syndrome requiring fasciotomy 2
• Sexual dysfunction and erectile dysfunction 1, 3

Treatment Approach Selection

Endovascular Repair (EVAR)

• Preferred first-line approach for moderate-to-high surgical risk patients with suitable anatomy 1
• Requires non-aneurysmal distal landing zone within the common iliac arteries 4
• Modified endovascular techniques with pelvic revascularization should be considered at specialized centers when standard EVAR would require internal iliac artery sacrifice 4, 3
• Technical success rates for catheter-based interventions range from 67-100% 5

Open Surgical Repair

• Reserved for patients with unsuitable anatomy for EVAR or when endovascular approaches fail 1
• Involves resection with interposition grafting 6
• Higher perioperative morbidity including myocardial infarction, acute kidney injury, and dialysis initiation compared to EVAR 1

Concomitant Abdominal Aortic Aneurysm

When both AAA and iliac aneurysms are present, repair both simultaneously if the iliac aneurysm is ≥3.5 cm, even if the AAA has not reached its own repair threshold 1. This is critical because:

• 20-40% of AAA patients have concomitant common iliac artery aneurysms 1
• Iliac aneurysms often reach repair size before the associated AAA 1
• Adequate AAA repair frequently requires treatment of iliac ectasia or aneurysms 1

Monitoring and Follow-up

• Patients undergoing catheter-based intervention require close monitoring for abdominal pain, which may indicate complications 5
• Post-EVAR patients have higher rates of late reintervention compared to open repair 1
• Ischemic complications occur in approximately 9% of EVAR patients, which may exceed open surgical repair rates 2

Common Pitfalls to Avoid

• Never sacrifice both internal iliac arteries without attempting revascularization techniques 1, 3
• Do not rely solely on angiography to assess iliac aneurysm size, as mural thrombus causes underestimation; use duplex ultrasound or CT angiography 1
• Avoid delaying repair in symptomatic patients or those with rapid growth, even if size threshold not yet met 1
• Recognize that pelvic ischemia can occur from atheroembolization even when hypogastric circulation is preserved 2