Delayed Posttreatment Residual Flow into Aneurysm After Flow Diverter Placement

Area of Science:

• Neuroendovascular surgery
• Cerebrovascular disease management

Background:

• Delayed aneurysmal rupture is a concern following flow diverter (FD) treatment due to assumed post-treatment inflow.
• The clinical significance of residual flow detected months after FD placement remains unclear.

Observation:

• A single Pipeline Embolization Device (PED) was used to treat a large intracranial aneurysm.
• Initial post-procedure angiography showed flow stagnation, but a 6-month follow-up revealed delayed residual flow into the aneurysm sac.
• The patient's planned re-intervention was deferred, and dual antiplatelet therapy was continued.

Findings:

• Despite delayed residual flow at 6 months, the aneurysm completely thrombosed by 12 months post-procedure.
• This case suggests that delayed residual flow may not impede eventual aneurysm occlusion.

Implications:

• Delayed residual flow post-FD placement might be a normal clinical course, not necessarily indicating a need for further intervention.
• Further research is required to determine optimal follow-up strategies and the necessity of additional procedures for patients with delayed residual flow.