Safety And Efficacy of the Neuroform Atlas Stent for Treatment of Intracranial Aneurysms: A Systematic Review, Meta-Analysis and Meta-Regression

Background: Intracranial aneurysms (IAs) are the major cause of subarachnoid hemorrhage. Stent-assisted coiling, especially with the Neuroform Atlas stent (NAS), has proven more effective than coiling alone for treating these aneurysms.

Purpose: To perform a systematic review and meta-analysis to investigate the efficacy and safety of NAS in treating IAs.

Data sources: A comprehensive literature search was conducted on PubMed, Embase, Cochrane CENTRAL library, and clinicaltrials.gov from inception till June 2024.

Study selection: We included studies on ruptured and unruptured IAs treated with the NAS, covering experimental, observational, and case series across all age groups. The aneurysm occlusion rate was assessed using the Raymond-Roy classification (RROC). The modified Rankin Scale (mRS) and adverse events related to stent use were also recorded.

Data analysis: The statistical analysis was conducted on R version 4.3.2 using the packages "meta" and "metasens". We reported our results as proportions with their corresponding confidence intervals (CIs). Meta-regression, leave-one-out and sensitivity analyses were conducted to confirm the robustness of our results.

Data synthesis: A total of 42 studies including 2434 participants with a mean age of 51 to 73 years were included. Among angiographic outcomes, the final RROC 1/RROC 2 was achieved in 95% of the patients, final RROC 1 in 82%, RROC 2 in 12%, and RROC 3 in 5% of the patients. Additionally, 93% of the patients showed mRS grade 0, 5% showed mRS grade 1, 3% showed mRS grade 2, 2% showed mRS grade 3, 0% showed mRS grade 4, 0% showed mRS grade 5, and 1% showed mRS grade 6. All adverse events had a ≤ 5% rate.

Limitations: Due to limited cause-specific data, we were unable to analyse mortality specific to the stent placement and complications. Despite the large number of studies included, comparative studies were still observed to be scarce.

Conclusions: Although the generalizability of our findings is limited, this study demonstrates that NAS is highly effective for treating IAs, with high occlusion rates and a low incidence of adverse events. The stent's performance, supported by comprehensive analysis, highlights its safety and efficacy in managing both ruptured and unruptured aneurysms.

Abbreviations: NAS = Neuroform Atlas stent; IA = Intracranial aneurysm; SAC = stent-assisted coiling.