Coiling as a Rescue Strategy for Flow Diverter Prolapse into a Giant Intracranial Aneurysm

Up to 3.2% of the adult population has an unruptured intracranial aneurysm (IA). Flow diversion is a relatively new treatment technique that is especially useful for large and morphologically unfavorable IAs.

A previously healthy woman aged 32 years presented with a 6-month history of ptosis and ophthalmoplegia of the left eye. A magnetic resonance imaging scan revealed a giant left internal carotid artery aneurysm. She was admitted for treatment using flow diversion. After delivery of the flow diverter (FD), prolapse of the proximal end of the stent into the aneurysmal sac was observed. FD stabilization was achieved by deploying multiple coils through a previously placed microcatheter to push the prolapsed end away from the aneurysmal lumen.

The patient had a favorable outcome, with reduction of preoperative mass effect symptoms and complete obliteration of the aneurysm persisting at the 3-month follow-up.

Giant IAs remain one of the most daunting clinical problems to treat. FD displacement is a rare (0.5%-0.75%) and possibly fatal complication. Currently, no clinical guidelines exist for its management. Adjunctive coiling is a possible rescue strategy for stabilizing an FD that foreshortened and prolapsed into the aneurysmal sac. Further studies are needed to identify the best approach to this complication.