Keywords: مطالعه بین المللی آئوریسم داخل شکمی; Natural history; Quality of life; Unruptured aneurysms; CI; Confidence interval; HR; Hazard ratio; ISUIA; International Study of Unruptured Intracranial Aneurysms; SAH; Subarachnoid hemorrhage; UCAS; Unruptured Cerebral Aneurysm Study;