Aneurysmal subarachnoid haemorrhage (aSAH) is associated with significant morbidity and mortality. The International Subarachnoid Aneurysm Trial (ISAT) reported reduced morbidity in patients treated with endovascular coiling versus surgical clipping. However, recent studies suggest that there is no significant difference in clinical outcomes. This study examines the outcomes of either technique for treating aSAH during the 15 years post-ISAT at a Canadian quaternary centre.

We reviewed prospectively collected data of patients admitted with aSAH from January 2002 to December 2017. Glasgow Outcome Scale (GOS) was compared at discharge, 6 months and 12 months’ follow-up using univariate and multivariable ordinal logistic regression. Post-operative complications were assessed using binary logistic regression.

Two-hundred and eighty-seven patients were treated with coiling and 95 patients with clipping. The mean age of clipped patients was significantly younger, and hypertension was significantly commoner in coiled patients. A greater proportion of coiled aneurysms were located in the posterior circulation. No difference in the odds of having a favourable GOS was seen between patients who were clipped versus coiled at any of follow-up time points on univariate or multivariable analysis. In both treatment groups, patient recovery to independence (GOS 4–5) was seen from discharge to 6 months, but not from 6 to 12 months’ follow-up, without difference between clipping and coiling.

These real-world findings suggest clipping remains an effective and important treatment option for patients with aSAH who do not meet ISAT inclusion criteria. The results can assist in clinical decision-making processes and understanding of the natural recovery progression of aSAH.