Longitudinal evaluation of neointimal formation using optical coherence tomography for an intracranial aneurysm with flow diverter placement in vivo: preliminary experience.

Placement of a flow diverter (FD) has been a mainstream treatment for intracranial aneurysms. Neointimal formation in the aneurysmal neck and stent struts is important for promoting aneurysm healing and reducing ischemic complications. Although several animal studies have reported the longitudinal evaluation of neointimal formation post-FD placement using optical coherence tomography (OCT), no human studies have been published. We describe the first case of a patient with follow-up longitudinal angiography and OCT examination at 1 and 3 months post-FD placement for an internal carotid artery aneurysm. At 1 month, the OCT images showed complete neointimal formation on stent struts of the parent artery and partial neointimal formation on the neck. The aneurysm was occluded on angiography at 3 months and all stent struts were covered with neointima on OCT images. An OCT examination may provide insights regarding the mechanism underlying the healing process of aneurysms treated by an FD.