Epidemiology, Therapy and Functional Outcome of Aneurysmal Subarachnoid Hemorrhage in Sapporo Between 2003 and 2007: An Area-specific, Group-based Study by Hokkaido University Hospital Group

Recent multi-center studies in Western countries have clarified various aspects of aneurysmal subarachnoid hemorrhage (SAH) as part of evidence-based medicine (EBM). In Japan, however, much less evidence on aneurysmal SAH has been established. In this study, therefore, we prospectively enrolled 836 patients with aneurysmal SAH admitted to Hokkaido University Hospital and its affiliate hospitals in Sapporo area between 2003 and 2007, and analyzed their epidemiology, therapy and functional outcome. Of totally 836 patients, 130 (15.6%) and 214 (25.6%) were categorized into WFNS Grade 4 and 5, respectively. Totally, 689 patients (82.4%) underwent some interventions for ruptured aneurysms, including surgical clipping in 548 patients and endovascular coiling in 121. Of these, favorable functional outcome at 1 month after the onset was obtained in 461 patients (66.9%). Multivariate logistic regression analysis revealed that age, neurological severity, intracerebral hematoma, symptomatic vasospasm, and normal pressure hydrocephalus were independent predictors for poor functional outcome. The present results suggest the importance of prospective multi-center, cohort or randomized study on aneurysmal SAH in Japan.