Background: Endovascular treatment (EVT) is widely accepted for intracranial aneurysms due to its safety and efficacy. However, EVT of ruptured very small intracranial aneurysms (RVSIA) (3 mm) is still challenging and the risk-benefit ratio of EVT remains unclear. The aim of this study was to evaluate the safety and efficacy of EVT of RVSIA.<break><break>Methods: We performed a systematic review and meta-analysis of the studies on EVT of RVSIA. Pooled prevalence rates were calculated for initial and follow-up complete occlusion rates (Raymond Roy Grade 1), recanalization, retreatment, long-term favorable outcome (modified Rankins scale score 0 to 2 or Glasgow Outcome Scale 4 or 5), procedure-related complications (coil herniation, thromboembolism, and intraprocedural re-rupture), and procedure-related mortality. Pooled odds ratios were calculated to compare these outcomes between simple coiling and stent-assisted coiling (SAC).<break><break>Results: Of the 600 studies screened, 24 studies with a total of 1355 RVSIAs treated with EVT were included. The initial and follow-up complete aneurysm occlusion rates were 64% (95% confidence interval [CI]: 5274%) and 85% (95% CI: 7492%). The rates of recanalization and retreatment were 6% (95% CI: 310%) and 3% (95% CI: 24%). The favorable long-term follow-up outcome was observed in 91% (95% CI: 8993%) of patients. The rates of coil herniation, thromboembolism, and intraprocedural rupture were 2% (95% CI: 18%), 4% (95% CI: 36%), and 4% (95% CI: 27%), respectively. Mortality was 3% (95% CI: 24%). Comparison of outcomes between simple coiling and SAC revealed no significant difference, except for a higher likelihood of recanalization in the coiling group (Odds ratio, 3.51 [95% CI, 1.319.45]).<break><break>Conclusions: Our meta-analysis demonstrates that EVT for RVSIA is a feasible, effective, and safe approach that is associated with favorable clinical outcomes in both the short and long term.

H. Matsukawa received a non-related lecture fee from Daiichi-Sankyo and consulting services fee from B. Braun. K. Uchida received a non-related lecture fee from Daiichi-Sankyo, Bristol-Myers Squibb, Stryker, and Medtronic. S. Yoshimura received a non-related lecture fee from Stryker, Medtronic, Johnson & Johnson, Kaneka Medics. A. Spiotta Research support (STAR) Avail, RapidAI, Penumbra, Microvention, Medtronic, Stryker, Brain Aneurysm Foundation. Consulting RapidAI, Avail, Penumbra, Medtronic.

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Source of funding: None

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The data that support the findings of this study are available from the corresponding author, Alejandro M Spiotta, upon reasonable request.

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