Five-Year Efficacy and Safety of the FRED Flow-Diverting Stent for Intracranial Aneurysms: Results From a Prospective Cohort

BACKGROUND: Flow diversion is a well-established endovascular treatment for intracranial aneurysms, yet long-term outcome data remain scarce. Our aim was to report efficacy and safety at 5 years for the flow redirection endoluminal device in a consecutive cohort with protocolized follow-up. METHODS: All consecutive patients with intracranial aneurysms treated with a flow redirection endoluminal device between December 2015 and July 2020 at 2 university hospitals were included in a prospective registry. Treatment decisions and procedural protocols were standardized. Clinical and imaging follow-up, including scheduled 3-dimensional rotational digital subtraction angiography, continued through August 2025. The primary end point was complete or near-complete occlusion at 5 years, defined as O’Kelly-Marotta (angiographic grading scale) grades C to D. Ischemic, hemorrhagic, and device-related events were prospectively recorded. RESULTS: A total of 203 patients (mean age, 54.7 years; 77.3% women) with 236 intracranial aneurysms were analyzed. At 5 years, complete or near-complete occlusion (O’Kelly-Marotta grades C–D) was achieved in 225 aneurysms (95.3%), comprising 203 of 211 (96.2%) in the anterior circulation and 22 of 25 (88.0%) in the posterior circulation. Retreatment was required in 5 aneurysms (2.1%), all treated before 2019. Symptomatic complications occurred in 12 of 203 patients (5.9%): 10 ischemic (4.9%) and 2 hemorrhagic (1.0%); no treatment-related deaths, rebleeding, or delayed rupture occurred. One patient had moderate permanent disability, and one died from a contralateral hypertensive hemorrhage deemed unrelated to the device. Asymptomatic device-related findings occurred in 22 of 236 aneurysms (9.3%). CONCLUSIONS: Flow redirection endoluminal device achieved durable aneurysm occlusion with a low rate of clinically relevant complications. These findings support sustained efficacy and safety across diverse aneurysm morphologies and locations.