Comparison of efficacy and safety between Neuroform Atlas stent-assisted coiling and coiling alone for irregular intracranial aneurysms: a single-center retrospective study.
Zou J, Lai L, et al. • Neurosurgical review • 2026
Neuroform Atlas stent-assisted coiling was associated with higher long-term complete occlusion rates and lower recurrence compared with coiling alone for irregular intracranial aneurysms, but also with higher costs and more asymptomatic cerebral infarctions.
Key Findings
Results
The SAC and coiling alone groups had significant baseline differences in aneurysm morphology and rupture status.
The SAC group had wider necks than the coiling alone group (4.27 ± 1.54 vs. 3.55 ± 1.26 mm, P < 0.001).
The SAC group had smaller dome-to-neck ratios (1.29 ± 0.48 vs. 1.77 ± 0.80, P < 0.001).
The SAC group had a higher proportion of unruptured aneurysms (42.7% vs. 14.0%, P < 0.001).
A total of 210 aneurysms were included: 103 in the SAC group and 107 in the coiling alone group, treated between January 2022 and December 2023.
Results
There was no significant difference in immediate complete occlusion rates between the SAC and coiling alone groups.
Immediate complete occlusion was achieved in 84.5% of the SAC group vs. 91.6% of the coiling alone group (P = 0.111).
This finding indicates that SAC did not confer an early occlusion advantage over coiling alone.
Results
At last angiographic follow-up, the SAC group had a significantly higher complete occlusion rate than the coiling alone group.
Complete occlusion at last follow-up was 93.0% in the SAC group vs. 74.6% in the coiling alone group (P = 0.004).
Mean follow-up duration was 6–8 months.
This represents an improvement from immediate post-procedure rates in the SAC group and a decline in the coiling alone group.
Results
The SAC group had a significantly lower aneurysm recurrence rate at follow-up compared to the coiling alone group.
Recurrence rate was 5.6% in the SAC group vs. 22.0% in the coiling alone group (P = 0.012).
Angiographic follow-up was conducted at a mean of 6–8 months post-procedure.
Results
Favorable clinical discharge outcomes were higher in the SAC group, but this difference was not sustained at 1-year follow-up.
Favorable discharge outcomes (mRS ≤ 2) occurred in 89.3% of the SAC group vs. 74.8% of the coiling alone group (P = 0.006).
At 1-year follow-up, favorable outcomes were 90.3% in the SAC group vs. 85.0% in the coiling alone group (P = 0.249), a non-significant difference.
The early clinical advantage of SAC was not maintained over longer-term follow-up.
Results
Asymptomatic cerebral infarction occurred significantly more frequently in the SAC group than in the coiling alone group.
Asymptomatic cerebral infarction incidence was 16.5% in the SAC group vs. 7.5% in the coiling alone group (P = 0.043).
These events were asymptomatic, meaning patients did not have clinically apparent neurological deficits from these infarctions.
Results
Hospitalization costs were significantly higher in the SAC group compared to the coiling alone group.
Mean hospitalization costs were $20,906 in the SAC group vs. $18,284 in the coiling alone group (P = 0.008).
This cost difference reflects the additional resources associated with stent-assisted coiling procedures.
What This Means
This study compared two approaches to treating irregular intracranial aneurysms (bulges in brain arteries with complex shapes): using a Neuroform Atlas stent alongside coil embolization versus using coils alone. Researchers reviewed records from 210 patients treated at a single center over two years. They found that while both groups had similar rates of aneurysm closure immediately after the procedure, patients who received the stent-assisted approach were more likely to have their aneurysm completely closed at follow-up (around 6–8 months later) and were much less likely to experience aneurysm recurrence. These findings suggest the stent may help hold coils in place more effectively over time.
However, the stent-assisted approach came with trade-offs. Patients in the stent group were more likely to develop small, silent strokes (asymptomatic cerebral infarctions) detected on imaging — 16.5% versus 7.5% — though these did not cause obvious symptoms. The stent procedure also cost more. While patients in the stent group had better short-term functional outcomes at hospital discharge, this advantage disappeared by the one-year mark, when both groups had similar rates of good functional outcomes.
This research suggests that stent-assisted coiling with the Neuroform Atlas device may offer better long-term aneurysm closure for difficult irregular aneurysms, but clinicians and patients should weigh this benefit against higher costs and a greater risk of silent brain infarctions. The study's retrospective design and significant baseline differences between groups — such as more unruptured aneurysms and wider-necked aneurysms in the stent group — mean that results should be interpreted cautiously, and future randomized studies would be needed to confirm these findings.
Zou J, Lai L, Chen C, Zhang C, Jiang Z. (2026). Comparison of efficacy and safety between Neuroform Atlas stent-assisted coiling and coiling alone for irregular intracranial aneurysms: a single-center retrospective study.. Neurosurgical review. https://doi.org/10.1007/s10143-026-04524-2