Visceral Aneurysm Embolization

Background and indications

Endovascular embolization of visceral artery aneurysms (splenic, hepatic, renal, mesenteric arteries) is the first-line treatment for these aneurysms. Visceral aneurysms are rare (0.1-2% of population) but carry potentially fatal rupture risk. Splenic artery is the most common location (60%), followed by hepatic artery (20%).

Treatment is indicated for symptomatic aneurysms, aneurysms ≥ 2 cm (rupture threshold), expanding aneurysms, and all aneurysms in women of childbearing age (increased rupture risk during pregnancy).

Pre-procedure assessment

Assessment includes CT angiography with 3D reconstructions (morphology, size, necks, collateral branches), and evaluation of treatment options (embolization vs surgery vs covered stent depending on anatomy). Mycotic (infectious) aneurysms require infectious workup and associated antibiotic therapy.

Procedure

Under local anesthesia and sedation, a catheter is introduced through the femoral artery. Under fluoroscopic guidance, the aneurysm is selectively catheterized. Several techniques are used depending on morphology: coil packing in the aneurysm sac (saccular aneurysms), "sandwich" embolization (upstream and downstream coil occlusion), covered stent (stent-graft) excluding the aneurysm (if favorable neck and parent artery to preserve), or glue injection for complex cases. The procedure takes 1 to 3 hours.

Results and scientific evidence

Endovascular embolization offers 90-98% technical success rate with 5-10% recurrence rate. For splenic artery aneurysms, embolization is superior to surgery in terms of morbidity. Organ function preservation rate (spleen, liver, kidney) is 85-95% thanks to selective embolization techniques.

Risks and complications

Partial splenic infarction (10-20% for splenic aneurysms, usually asymptomatic), post-embolization syndrome (10-20%), coil migration (< 2%), organ ischemia (< 3%), intra-procedural rupture (< 1%). Elective mortality is < 1%, versus 25-70% for untreated rupture.

Recovery

1-2 night hospitalization. Control CT angiography at 3-6 months then annually to verify durable aneurysm exclusion.

Practical information

The procedure is performed as a short inpatient stay. It is performed by a vascular interventional radiologist, in coordination with the vascular surgeon.