Diffusion-weighted imaging–detected ischemic lesions associated with flow-diverting stents in intracranial aneurysms: safety, potential mechanisms, clinical outcome, and concerns

OBJECT It was initially considered safe for flow-diverting stents to cover the ostia of branching vessels during endovascular procedures for the treatment of intracranial aneurysms. As more recent evidence suggests, however, their use is not always free of ischemic concerns in terms of covered arterial ostia. The authors sought to determine the frequency of silent and clinically evident diffusion-weighted imaging (DWI)–detected abnormalities related to stent placement as a means of elucidating potential clinical risks. METHODS This is a prospective single-center study on a series of patients with intracranial aneurysms that were treated with flow-diverting stents. All patients systematically underwent an MRI protocol that included DWI before treatment, between 24 and 48 hours postprocedure, and 3 months postembolization. Effectiveness of anticoagulation treatment was assessed for all patients. Lesions seen on DWI were correlated to the parent artery and the side-branch territories and were statistically a...