Abstract
An unruptured cerebral aneurysm study in Japan (UCAS Japan) is being conducted to clarify the natural course and treatment risks of unruptured cerebral aneurysms (UCA), and build national data bank. This is a prospective cohort study and the enrolled patients are cases with newly diagnosed UCA after January. 1, 2001. Data of all patients with UCA, either treated or observed, is stored in the head-quarter computer through internet registration. All cases are scheduled to have a periodic follow-up at 3 months, 12 months and 36 months after the diagnosis. Registered data includes patient's demographics, neurological status, past and family history, and aneurysmal characteristics. During the last 17 months, we had 2,979 new patients (3,667 aneurysms) with UCA registered from 385 institutions. So far, there is a difference in registry status between geographic locations in Japan. Male-female ratio was 1 : 2 and median age of patients was 63-year-old. Size of aneurysm ranged from 3〜45 mm (median 5 mm). The most frequent reason for imaging, which leaded to diagnosis of UCA, were ill-defined symptoms such as headache or dizziness. Multiple aneurysms was found in 18% of cases and 96% of aneurysms were saccular ones. At the first registration, craniotomy was indicated in 35% and endovascular treatment in 4% of cases. A three months follow-up was reported in 2,327 cases and a 12 months report in 579 cases. Treatment was performed in 943 cases with 1,074 aneurysms. Detailed protocol for this study can be reviewed at internet homepage https://endai.umin.ac.jp/islet/ucasj/. We are planning to call for further patient enrollment and conform a reliable data source to direct future management of UCA.
