Objective: The Flow-Redirection Endoluminal Device X (FRED X) is a newer generation flow diverter with surface modifications aimed at minimizing thrombogenicity. At present, data on its long-term efficacy are limited. This multicenter study presents the largest series within the United States describing the device's efficacy, safety, and long-term outcomes in treating cerebral aneurysms of varying morphology.

Methods: Patients treated with the FRED X for a cerebral aneurysm between February 2022 and February 2024 at 6 high-volume centers across the United States were included. Data were collected regarding demographics, clinical presentation, and procedural efficacy. Angiographic and clinical follow-up outcomes were assessed at 6 and 12 months.

Results: A total of 154 patients with 162 aneurysms were treated with 164 FRED X devices over the study period. Overall, 81.8% of the cohort was female with a mean age of 56.8 years. The authors observed satisfactory rates (≥ 99.3%) of device deployment and good wall apposition and neck coverage. One hundred forty-seven (95.5%) patients were functionally independent at discharge (modified Rankin Scale scores 0-2). Rates of adequate occlusion (Raymond-Roy Occlusion Scale score I or II) increased from 84.2% at 6 months to 83.5% at the 12-month follow-up, while rates of in-stent stenosis decreased. All patients (100%) who underwent follow-up were functionally independent at 6 months, and 95.9% were functionally independent at 12 months.

Conclusions: This multicenter cohort study demonstrates the ease of FRED X deployment with an adequate safety profile, with low rates of procedural complications and favorable outcomes on follow-up. Rates of aneurysm occlusion increased over time, with a subsequent decrease in stent-associated complications.