Table 1.
Annual rupture rates and risk factors for UCA rupture in large cohort studies
| Study and year of publication | Country | Inclusion criteria | No. of patients | No. of aneurysms | FU durations (mean) | Age (years) (mean ± SD) | Aneurysm size (mm) (mean ± SD) | Annual rupture rate (%) | Risk factors for UCA rupture |
|---|---|---|---|---|---|---|---|---|---|
| ISUIA,7) 2003 | USA, Canada, and Europe | General population, ≥2 mm | 1692 | 2686 | 4.1 years | 55.2 ± 13.1 | 7.4 ± .6.9 | 0.8 | ≥7 mm, BA tip, IC-PComA |
| Ishibashi, et al.,8) 2009 | Japan | General population | 419 | 529 | 905.3 days | 60.8 ± 11.4 | 4.5 ± 3.5 | 1.4 | History of SAH, ≥10 mm, Posterior circulation |
| SUAVe study,9) 2010 | Japan | General population, <5 mm | 374 | 448 | 41.0 months | 61.9 ± 10.3 | 3.3 ± 0.9 | 0.54 | <50 yrs, Hypertension, ≥4 mm, Multiplicity |
| UCAS Japan,2) 2012 | Japan | General population, ≥3 mm | 5720 | 6697 | 635.9 days | 62.5 ± 10.3 | 5.7 ± 3.6 | 0.95 | ≥7 mm, AComA, IC-PComA, Irregular shape |
| Juvela, et al.,11) 2013 | Finland | General population | 142 | 181 | 21.6 years | 41.8 ± 10.8 | 5.1 ± 3.7 | 1.1 | Age inversely related, Smoking, ≥7 mm, AComA |
| Hishikawa, et al.,12) 2015 | Japan | Elderly patients (>70 years) | 1896 | 2227 | 802.7 days | 74.3 ± 3.9 | 6.2 ± 3.9 | 1.6 | >80 years, ≥7 mm, IC-PComA |
AComA: anterior communicating artery, BA: basilar artery, FU: follow-up, IC-PComA: internal carotid-posterior communicating artery, ISUIA: International Study of Unruptured Intracranial Aneurysms, SAH: subarachnoid hemorrhage, SD: standard deviation, SUAVe: Small Unruptured Intracranial Aneurysm Verification, UCAs: unruptured cerebral aneurysms, UCAS: Unruptured Cerebral Aneurysm Study.