Patient Management After Flow Diversion for Unruptured Intracranial Aneurysms: a Literature Review and DELPHI...

Unruptured intracranial aneurysms are a common and can have devastating outcomes if ruptured. Flow diversion has expanded treatment options, especially for wide-necked and blister aneurysms. Yet, optimal follow-up retreatment strategies in case of treatment failure remain unclear. A DELPHI consensus was initiated to understand current practice in aneurysm management after flow diverter treatment.

This DELPHI consensus was conducted during the 5 T Think Tank, following a scoping literature review. Experts discussed the results, responded to iterative questionnaires, which started with four open-ended questions, and concluded with ten closed-ended questions.

Of the 40 attendees, 24 participants (60%) identified as experts in flow diversion and participated in the DELPHI process, which involved a literature search and three DELPHI rounds. Consensus was reached on performing the first assessment of the flow diverter during the procedure using cone-beam CT (77.8%), and on timing of the first follow up (at 6 months, 70.8%). For follow-up timing, an annual (57%) or semi-annual (43%) schedule was favored. No preference emerged for the follow-up imaging modality, with slight preferences for MRA (29%), followed by DSA (25%), DSA + MRA (21%), CTA (17%), and DSA + CTA (8%). Aneurysm growth (> 2 mm) was identified as a key criterion for retreatment. It was thought that combining clinical and angiographic metrics should be a key research priority, as it could potentially improve retreatment decision making compared to a purely angiographic outcome.

This DELPHI consensus highlights the complexity of decision-making for unruptured intracranial aneurysms. Despite these challenges, there was consensus among international experts on follow-up timing and decision drivers for retreatment.