Pipeline embolization device induced collateral channels in elective flow diversion treatment

Area of Science:

• Neuroendovascular therapy
• Cerebrovascular diseases
• Medical device technology

Background:

• The pipeline embolization device (PED) is utilized for treating intracranial aneurysms.
• Uncertainty exists regarding PED's impact on cerebral blood flow alteration.
• Persistent perfusion and non-regression of treated aneurysms highlight these uncertainties.

Observation:

• A 68-year-old woman with a giant fusiform paraophthalmic aneurysm was treated with a PED.
• Following reduced antiplatelet therapy to encourage thrombosis, a perfused aneurysmal remnant enlarged.
• Angiography showed PED occlusion but a new collateral channel feeding the remnant.

Findings:

• The 'thrombosed' aneurysm remnant demonstrated internal vascularity on cone beam CT angiography.
• Vascular enhancement on MRI confirmed the remnant's biological activity.
• A peri-construct collateral channel developed, supplying the remnant and contributing to middle cerebral artery flow.

Implications:

• Apparently thrombosed aneurysmal remnants can be biologically active and remodel.
• Flow dynamics and collateral formation around PEDs require further investigation.
• Understanding these processes is crucial for managing post-treatment aneurysm behavior and outcomes.