Background and objectives: Flow diversion induces progressive aneurysm occlusion by reducing blood flow across the aneurysm neck over time. Various factors, including comorbid conditions, aneurysm characteristics, and stent design, have been shown to affect occlusion rates after flow diversion. Our study analyzed predictors of angiographic occlusion after flow diversion of intracranial aneurysms using the Flow Redirection Endoluminal Device with X-technology (FRED-X).

Methods: This was a multicenter study of ruptured and unruptured aneurysms treated at 6 participating institutions across the United States. Data were collected on patient-specific factors and aneurysm characteristics. Angiographic occlusion was assessed using the Raymond Roy Occlusion Classification. Multivariate logistic regression was used to analyze predictors of complete angiographic occlusion at either the 6- or 12-month follow-up.

Results: One hundred forty-four patients with 152 aneurysms met criteria for inclusion. A total of 69.4% of patients (n = 100) achieved complete occlusion. The average age of the cohort that achieved complete occlusion was 56.2 years, and 84% (n = 84) was female. On univariate analysis, aneurysm laterality, partial thrombosis of the aneurysm sac, proximal and distal diameters of the parent artery, and procedure time were significantly associated with complete angiographic occlusion. On multivariate analysis, parent artery diameter distal to the aneurysm was associated with 0.46-fold decreased odds of complete occlusion (95% CI: 0.26-0.78, P < .002). One patient in the incompletely occluded cohort underwent retreatment using the Pipeline Shield at 7 months after the initial flow diversion procedure using the FRED-X.

Conclusion: Our study identified that parent artery diameter distal to the aneurysm was associated with decreased odds of aneurysm occlusion after flow diversion using the FRED-X. This adds to the literature on the importance of device sizing during flow diversion. Further prospective studies could help validate these findings.