Can endovascular flow diversion be used for ophthalmic Internal Carotid Artery (ICA) aneurysms with the ophthalmic artery originating from the aneurysm?

Flow Diversion for Ophthalmic ICA Aneurysms with Ophthalmic Artery Origin from the Aneurysm

Flow diversion is a safe and effective treatment option for ophthalmic internal carotid artery (ICA) aneurysms where the ophthalmic artery originates from the aneurysm, but outcomes may be less favorable when the artery originates specifically from the aneurysm dome rather than the neck. 1, 2

Efficacy and Safety Considerations

Anatomical Relationship Impact

The anatomical relationship between the ophthalmic artery origin and the aneurysm significantly affects treatment outcomes:

• Type 1: Ophthalmic artery separate from aneurysm - Best outcomes
• Type 2: Ophthalmic artery from aneurysm neck - Good outcomes
• Type 3: Ophthalmic artery from aneurysm dome - Less favorable outcomes 2

When the ophthalmic artery originates from the aneurysm dome (Type 3), there is:

• Lower rate of complete aneurysm occlusion (statistically significant, p=0.0297)
• Trend toward more visual deficits (p=0.0797)
• Lower rate of ophthalmic artery patency (p=0.0783) 2

Occlusion Rates and Visual Outcomes

• Complete occlusion rates for carotid-ophthalmic aneurysms treated with flow diversion range from 64.9% at 6 months to 96% at 3 years 1
• Risk of permanent adverse visual outcomes is low when flow diversion is used for ophthalmic segment aneurysms 1
• Transient visual deficits occur in approximately 3% of cases 2

Treatment Decision Algorithm

1. Evaluate aneurysm characteristics:

   • Size and morphology
   • Neck width (wider necks predict higher recanalization with traditional coiling) 3
   • Precise origin of ophthalmic artery relative to aneurysm

2. Consider alternative treatments first if:

   • Aneurysm is a ruptured saccular aneurysm amenable to primary coiling or clipping (Class 3: Harm recommendation against flow diversion) 4
   • Patient cannot tolerate dual antiplatelet therapy 4
   • Ophthalmic artery originates from the aneurysm dome (Type 3) 2

3. Favor flow diversion when:

   • Aneurysm has a wide neck not amenable to simple coiling or clipping (Class 2a recommendation) 5, 4
   • Aneurysm is fusiform/blister type (Class 2a recommendation) 5, 4
   • Ophthalmic artery originates from aneurysm neck (Type 2) or is separate from aneurysm (Type 1) 2

4. Consider adjunctive coiling with flow diversion:

   • Combined approach increases likelihood of complete aneurysm occlusion 6

Important Caveats and Pitfalls

1. Dual antiplatelet therapy requirements:

   • Flow diversion necessitates dual antiplatelet therapy
   • Higher risk of thrombogenicity compared to primary coiling 4
   • Increased risk of hemorrhagic complications, particularly with ventriculostomy 4

2. Age considerations:

   • Increasing age correlates with higher morbidity/mortality (OR per decade, 3.2; 95% CI, 1.23-8.49) 6
   • Younger patients (<40 years) may benefit more from surgical clipping for durability 5

3. Follow-up challenges:

   • Metal artifacts from stents complicate imaging surveillance 4
   • Long-term follow-up is essential to confirm occlusion and monitor for complications

4. Complication rates:

   • Overall morbidity rates around 7.4% and mortality rates around 3.7% 6
   • Postprocedural intracranial ischemia or hemorrhage reported in up to 24% of patients 7

Flow diversion represents an important treatment option for ophthalmic segment aneurysms, particularly those with challenging anatomy. However, the anatomical relationship between the ophthalmic artery and the aneurysm must be carefully evaluated to optimize outcomes and minimize complications.