Characteristics of study population and UIAs
| No. of Patients | UIAs (n = %) | P Value | ||
|---|---|---|---|---|
| Observed | Treated | |||
| 879 | (741; 66.8%) | (369; 33.3%) | ||
| Mean size of UIAs (mm) | 4.4 ± 0.1 | 7.8 ± 0.2 | ||
| Female sex (%) | 617 (70.2) | 527 (71.1) | 284 (77) | .039 |
| No. of UIAs | ||||
| Single | 422 (57.0) | 227 (61.5) | .146 | |
| Multiple | 319 (43.0) | 142 (38.5) | ||
| UIA associated with history of SAH from a separate ruptured aneurysm | 30 | 36 | <.001 | |
| Size of UIAs | ||||
| Small (<5 mm) | 534 (72.1) | 65 (17.6) | <.001 | |
| Medium (5–9.9 mm) | 175 (23.6) | 228 (61.8) | <.001 | |
| Large (10–24.9 mm) | 30 (4) | 72 (19.5) | <.001 | |
| Giant (> 25 mm | 2 (0.3) | 4 (1) | .081 | |
| Location of UIAs | ||||
| Internal carotid artery | 319 (43) | 205 (55.6) | <.001 | |
| Anterior cerebral artery | 136 (18.4) | 59 (16) | .329 | |
| Middle cerebral artery | 213 (28.7) | 66 (17.9) | <.001 | |
| Vertebrobasilar artery | 73 (9.9) | 39 (10.6) | .708 | |