Lower-Ischemic-Risk Profile of Coated Flow Redirection Endoluminal Device X Compared With Uncoated Flow Redirection Endoluminal Device Flow Diverter in the Treatment of Unruptured Intracranial Aneurysms.

Background and objectives: Flow Redirection Endoluminal Device (FRED) X is a new generation flow diverter with an antithrombotic surface coating. This study compares the procedural safety and short-term efficacy of FRED X with its uncoated predecessor, the FRED.

Methods: Patients treated with FRED and FRED X devices for unruptured aneurysms between 2013 and 2023 at 3 neurovascular centers were retrospectively reviewed. The procedural ischemic event rate was the safety end point, and the complete aneurysm occlusion rate at 1 year was the efficacy end point. Multivariable regression adjustment and 1:1 propensity score matching were performed to control for potential confounding.

Results: The FRED X group (137 patients) had a higher prevalence of recurrent and bifurcation aneurysms and fewer aneurysms with branch involvement than the FRED X group (156 patients). The ischemic event rate was lower in FRED X (1/156 [0.6%]) than in FRED (7/137 [5.1%]), which was significant after multivariable adjustment (odds ratio: 8.8, 95% CI: 1.1-72.7, P = .04), and tended to be significant in the propensity score analysis (P = .07). Morbidity was comparable between FRED (2.2%) and FRED X (0%, P = .10). The complete occlusion rates of FRED vs FRED X were 73/117 (62.4%) vs 39/54 (72.2%) aneurysms at 6 months (P = .21) and 52/74 (70.3%) vs 27/37 (73.0%) at 12 months (P = .77). Hemorrhagic complications, in-stent stenosis, and clinical events during follow-up and retreatments were not significantly different between groups.

Conclusion: This study indicates an improved ischemic risk profile of FRED X while maintaining a favorable efficacy profile, warranting further study and translation into clinical use.