Hydrocephalus and high Fisher grade blood distribution are strongly associated with post-procedural seizures in SAHSpecific brain conditions linked to seizures after aneurysm surgery

Endovascular aneurysm exclusion has revolutionized neurovascular care, yet postoperative seizures remain a significant cause of morbidity. As endovascular technologies evolve from simple coiling to complex flow diversion, identifying factors associated with postoperative seizures is essential for improving risk stratification and neurocritical care. This systematic review and meta-analysis, registered in PROSPERO (CRD420261375370), followed PRISMA 2020 guidelines. A comprehensive search of MEDLINE, Scopus, Embase, and the Cochrane Library was conducted through April 13, 2026. Studies published since 2016 investigating factors associated with seizures after endovascular treatment (coiling, flow diversion, or stent-assisted techniques) were included. Random-effects meta-analysis was performed using R to calculate pooled odds ratios (OR) and 95% confidence intervals (CI), with subgroup and sensitivity analyses performed where feasible. Six studies met the inclusion criteria for qualitative and quantitative synthesis. Radiological markers showed the strongest associations with post-procedural seizures. Hydrocephalus demonstrated the highest association (OR 3.91, 95% CI: 1.22 to 12.53), followed by Fisher grade 3 + 4 blood distribution (OR 3.29, 95% CI: 1.55 to 6.97, I2 = 0%). Regarding clinical grading, Hunt-Hess grade 1 to 3 was significantly associated with seizure occurrence (OR 3.15, 95% CI: 1.73 to 5.72), whereas WFNS grade 4 to 5 was also associated with seizure occurrence (OR 1.86, 95% CI: 1.14 to 3.02), although heterogeneity was moderate (I2 = 60.2%). Factors such as age, sex, MCA involvement, and cerebral oedema did not reach statistical significance (p > 0.05). Quality assessment using the Newcastle–Ottawa Scale (NOS) indicated overall moderate methodological quality, although the evidence was limited by observational study designs, heterogeneous seizure outcome definitions, and a small number of included studies. Radiological severity of the initial hemorrhage, particularly dense subarachnoid blood and secondary cerebrospinal fluid disturbances, was associated with a higher likelihood of postoperative seizures, whereas anatomical location and patient demographics showed no significant associations. These findings should be interpreted cautiously and may assist future risk stratification; however, they do not alone support specific antiepileptic prophylaxis strategies. Further prospective studies incorporating standardized seizure definitions and continuous EEG monitoring are warranted.Systematic review registrationhttps://www.crd.york.ac.uk/prospero/search, identifier CRD420261375370.