Patient and aneurysm characteristics
| Characteristic | Surgical | Endovascular |
| n=66 | n=70 | |
| Patient | ||
| Mean age at treatment, year (SD) | 56 (8) | 57 (7) |
| Female sex, n (%) | 41 (62%) | 53 (76%) |
| Pretreatment mRS score=0, n (%) | 55 (83%) | 47 (67%) |
| =1, n (%) | 10 (15%) | 19 (27%) |
| =2, n (%) | 0 | 3 (4%) |
| No mRS: patients not yet treated | 1 (2%) | 1 (2%) |
| Patients with multiple aneurysms | 12 | 18 |
| Index aneurysm | ||
| Location | ||
| Anterior circulation | 65 | 66 |
| Ophthalmic/paraophthalmic | 9 | 8 |
| Posterior communicating | 7 | 12 |
| Carotid terminus | 6 | 8 |
| MCA bifurcation | 18 | 15 |
| Anterior communicating | 19 | 13 |
| Other anterior circulation location | 6 | 10 |
| Posterior circulation | 1 | 4 |
| Index aneurysm size (mm), mean (range) | 8.7 (3–20) | 8.2 (3–23) |
| Aneurysm size 3–10 mm | 53 | 53 |
| Size 11–15 mm | 8 | 12 |
| Size 16–24 mm | 4 | 3 |
| Recurrent, previously treated index aneurysm | 1 | 1 |
| Symptomatic aneurysms | 12 | 10 |
| Pain/headache | 6 | 10 |
| Cranial nerve palsy | 2 | 0 |
| Stroke/TIA | 4 | 0 |
| History of previous SAH from another aneurysm | 7 | 7 |
| Hypertension | 34 | 31 |
| Current smoker | 26 | 30 |
| Excessive alcohol | 7 | 3 |
| Positive family history | 10 | 13 |
| Treatment | ||
| Time from randomisation to treatment, mean weeks (SD) | 14 (6) | 6 (1) |
| Adherence to assigned treatment, n (%) | 63/65 (97%) | 66/69 (96%) |
| Index aneurysm rupture after randomisation, prior to treatment | 1 | 0 |
| Additional non-index aneurysms treated at same time | 12 | 5 |
MCA, Middle Cerebral Artery; mRS, modified Rankin Scale; SAH, subarachnoid haemorrhage; TIA, transient ischemic attack.