Endovascular treatment of ruptured very small intracranial aneurysms: a systematic review and meta-analysis

BackgroundEndovascular 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. MethodsWe 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). ResultsOf 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]: 52-74%) and 85% (95% CI: 74-92%). The rates of recanalization and retreatment were 6% (95% CI: 3-10%) and 3% (95% CI: 2-4%). The favorable long-term follow-up outcome was observed in 91% (95% CI: 89- 93%) of patients. The rates of coil herniation, thromboembolism, and intraprocedural rupture were 2% (95% CI: 1-8%), 4% (95% CI: 3-6%), and 4% (95% CI: 2-7%), respectively. Mortality was 3% (95% CI: 2-4%). 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, 1.31-9.45]). ConclusionsOur 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.