Timing of aneurysm repair after subarachnoid haemorrhage: a systematic review and meta-analysis of ultra-early and early intervention

Objective

The optimal timing of aneurysm repair following aneurysmal subarachnoid haemorrhage (aSAH) remains uncertain. This systematic review and meta-analysis evaluated whether ultra-early (≤6h), early (≤12 h), or standard (≤24 h) treatment influences rebleeding, functional outcome, or mortality.

Methods

A systematic search of MEDLINE, EMBASE, and Scopus identified English-language studies published between 2000 and 2024 reporting outcomes after surgical or endovascular intervention within 24 h of aSAH. Pooled odds ratios (ORs) were calculated using random-effects models. Heterogeneity was assessed using the I² statistic. Poor functional outcome was defined as modified Rankin Scale score 3–6 at 6 months.

Results

Twenty-one studies comprising 8,108 patients were included. Ultra-early treatment (≤6h) was associated with a reduced risk of rebleeding (OR 0.21; 95 % CI 0.06–0.77), though this was based on two studies and should be interpreted cautiously. No mortality or functional outcome data were available for this subgroup. Early treatment (≤12 h) was associated with increased rebleeding risk (OR 2.36; 95 % CI 1.44–3.89) and no significant difference in functional outcome (OR 1.01; 95 % CI 0.47–2.15). Standard treatment (≤24 h) showed a directionally favourable estimate for functional outcome (OR 0.57; 95 % CI 0.33–1.00), though statistical significance was not reached. Mortality outcomes across all timing thresholds were inconclusive, with substantial heterogeneity observed.

Conclusion

Ultra-early aneurysm repair may reduce rebleeding, but current evidence is limited, underpowered, and insufficient to determine effects on survival or recovery. No consistent benefit was observed with early treatment. Further prospective, time-stratified studies are needed to define the optimal intervention window following aSAH.