Aneurysm characteristics
| Aneurysm characteristic | Results |
| Location, % (n/N) | |
| ICA, Extradural | 1.4% (12/851) |
| Cervical | 25.0% (3/12) |
| Petrous | 8.3% (1/12) |
| Cavernous | 66.7% (8/12) |
| ICA, Intradural | 38.0% (323/851) |
| Superior Hypophyseal | 15.8% (51/323) |
| Ophthalmic | 22.9% (74/323) |
| Posterior Communicating | 49.5% (160/323) |
| Anterior Choroidal | 3.1% (10/323) |
| ICA Terminus | 8.7% (28/323) |
| ACA | 30.7% (261/851) |
| Proximal to anterior communicating | 3.8% (10/261) |
| Anterior communicating | 87.4% (228/261) |
| Pericallosal | 8.8% (23/261) |
| MCA | 12.3% (105/851) |
| Proximal to MCA bifurcation | 14.3% (15/105) |
| MCA bifurcation | 77.1% (81/105) |
| Distal to MCA bifurcation | 8.6% (9/105) |
| Posterior circulation | 17.6% (150/851) |
| Vertebral | 8.0% (12/150) |
| Basilar trunk | 6.0% (9/150) |
| PICA | 10.7% (16/150) |
| AICA | 0.7% (1/150) |
| SCA | 10.0% (15/150) |
| Basilar bifurcation | 58.0% (87/150) |
| Distal location*, % (n/N) | 27.8% (237/851) |
| Bifurcation location†, % (n/N) | 49.8% (424/851) |
| Aneurysm size, % (n/N) | |
| Giant (>25 mm) | 0.2% (2/851) |
| Large (>10 to ≤25 mm) | 13.2% (112/851) |
| Medium (≥7 to ≤10 mm) | 25.4% (216/851) |
| Small (≥4 to <7 mm) | 43.9% (374/851) |
| Very Small (<4 mm) | 17.3% (147/851) |
| Aneurysm neck size, % (n/N) | |
| Non-wide-neck | 36.9% (307/833) |
| Wide-neck‡ | 63.1% (526/833) |
| Aneurysm rupture status, % (n/N) | |
| Ruptured | 31.0% (264/851) |
| Unruptured | 69.0% (587/851) |
*Distal locations are defined as aneurysms located in the anterior communicating artery or located distal to the middle cerebral artery (MCA) bifurcation.
†Bifurcation locations are defined as ICA terminus, MCA bifurcation, anterior communicating artery, and basilar artery bifurcation.
‡Wide neck defined as neck size ≥4mm or dome-to-neck ratio<2.
ACA, Anterior cerebral artery; AICA, Anterior inferior cerebellar artery; ICA, Internal carotid artery; MCA, Middle cerebral artery; PICA, Posterior inferior cerebellar artery; SCA, Superior cerebellar artery.