1196. Regrowth of a large intracranial aneurysm after on-label use of the Pipeline Embolization Device.

Authors: Ching-Jen Chen, MD; Mohana Patibandla; Min Park, MD; Kenneth Liu, MD; Yashar Kalani, MD, PhD (Charlottesville, VA)

Despite the widespread use of the Pipeline Embolization Device (PED), no aneurysm regrowth after its placement has been reported in the literature. We report the first case of aneurysm regrowth after initial follow-up angiography demonstrating near complete occlusion of the aneurysm and remodeling of the vessel with on-label PED use for a large 20×24×22mm (width×depth×height) cavernous segment internal carotid artery (ICA) aneurysm. The patient was treated with two overlapping PED (4.5×20mm and 5×20mm). Follow-up angiogram at four months after treatment demonstrated remodeling of the ICA with a small residual component measuring approximately 7×8×7mm. However, at 10 months after treatment, there was a complete regrowth of the aneurysm with interval growth, now measuring 25×28×18mm. Despite the high aneurysm occlusion rates reported with the PED, persistent aneurysm filling and aneurysm regrowth, although rare, should not be overlooked.