Both Atlas and Leo Baby stents afford similar angiographic and clinical efficacy for intracranial aneurysm embolization; however, the numerically higher complication rate observed with the Atlas stent should be interpreted with caution due to insufficient statistical power, and results should be considered hypothesis-generating rather than confirmatory.
Immediate post-procedural complete occlusion rates were similar between Atlas and Leo Baby stent groups.
Raymond grade distribution at 6-month follow-up showed no significant difference between the two stent groups.
Favorable clinical outcomes at 1 year were achieved in more than 90% of patients in both cohorts.
Peri-procedural complication rates were numerically higher in the Atlas group compared to the Leo Baby group, but this difference did not reach statistical significance.
The study was underpowered to detect potential differences in complication rates between the two stent types.
This research compared two types of small stents used to treat brain aneurysms — the Neuroform Atlas and the Leo Baby — in 96 patients treated over a two-year period. Stent-assisted coiling is a minimally invasive procedure where a stent is placed inside a blood vessel to hold tiny metal coils in place within the aneurysm, preventing it from rupturing. The Atlas stent has an open-cell, laser-cut design, while the Leo Baby uses a braided, closed-cell design; both can navigate through very narrow, winding blood vessels. The study found that both devices performed similarly in terms of how completely the aneurysm was sealed off immediately after the procedure, how well the results held up at a 6-month imaging follow-up, and how well patients were functioning one year later — with over 90% of patients in both groups having good functional outcomes. However, the study also found a notable numerical difference in complication rates: about 28% of patients receiving the Atlas stent experienced a peri-procedural complication, compared to 12% in the Leo Baby group. This difference was not statistically significant, meaning it could have occurred by chance. Critically, the researchers conducted an analysis showing that their study only had a 42% chance of detecting a real difference of this size — far below the standard 80% threshold considered adequate. This means the study may have simply been too small to confirm whether the difference in complications is real. This research suggests that both stents are effective tools for treating brain aneurysms, but the higher complication rate seen with the Atlas stent warrants further investigation in larger studies before firm conclusions can be drawn. The authors themselves emphasize that their findings should be considered preliminary and hypothesis-generating. Larger, prospective, multi-center studies will be needed to determine whether the observed difference in complications reflects a true difference between devices and to help guide clinicians in choosing between them for specific patients.
Zhu H, Xu J, Wang Y, Li Z, Yu J, Chao Y, et al.. (2026). A Retrospective Comparative Study of Leo Baby and Atlas Stents for the Treatment of Intracranial Aneurysms: Embolization Outcomes and Complications.. Journal of visualized experiments : JoVE. https://doi.org/10.3791/71816