Background: To determine the neurosurgeon's agreement in aneurysmal subarachnoid haemorrhage (aSAH) management with special emphasis on the rater's level of experience. A secondary aim was to analyse potential aneurysm variables associated with the therapeutic recommendation.

Method: Basic clinical information and admission computed tomography angiography (CTA) images of 30 consecutive aSAH patients were provided. Twelve neurosurgeons independently evaluated aneurysm characteristics and gave recommendations regarding the emergency management and aneurysm occlusion therapy. Inter-rater variability and predictors of treatment recommendation were evaluated.

Results: There was an overall moderate agreement in treatment decision [κ = 0.43; 95% confidence interval ((CI), 0.387-0.474] with moderate agreement for surgical (κ = 0.43; 95% CI, 0.386-0.479) and endovascular treatment recommendation (κ = 0.45; 95% CI, 0.398-0.49). Agreement on detailed treatment recommendations including clip, coil, bypass, stent, flow diverter and ventriculostomy was low to moderate. Inter-rater agreement did not significantly differ between residents and consultants. Middle cerebral artery (MCA) aneurysm location was a positive predictor of surgical treatment [odds ratio (OR), 49.57; 95% CI, 10.416-235.865; p < 0.001], while patients aged >65 years (OR, 0.12; 95% CI, 0.03-0.0434; p = 0.001), fusiform aneurysm type (OR, 0.18; 95% CI, 0.044-0.747; p = 0.018) and intracerebral haematoma (ICA) aneurysm location (OR, 0.24; 95% CI, 0.088-0.643; p = 0.005) were associated with a recommendation for endovascular treatment.

Conclusions: Agreement on aSAH management varies considerably across neurosurgeons, while therapeutic decision-making is challenging on an individual patient level. However, patients aged >65 years, fusiform aneurysm shape and ICA location were associated with endovascular treatment recommendation, while MCA aneurysm location remains a surgical domain in the opinion of neurosurgeons without formal endovascular training.