Patients selection

All consecutive patients in our institutional database who presented with a diagnosis of aneurismal SAH and ACoAAs on computed tomography angiography between January 2010 and December 2019 were included in our study. The exclusion criteria were as follows: (1) non-endovascular treatment; (2) timing of treatment >48 h; (3) non-aneurismal subarachnoid haemorrhage or inability to identify which aneurysm ruptured; (4) patients with ruptured IAs undergoing conservative or aneurysm clipping treatment and (5) incomplete clinical date or angiographic imaging.