Risk Factors for Re-bleeding of Aneurysmal Subarachnoid Hemorrhage: Systemic Review and Meta Analysis

Abstract

Abstract Objective : The mortality of re-bleeding is high and patients surviving are usually in poor clinical condition and have a worse outcome than patients with single bleed. We performed an update systemic review and Meta-analysis to determine the most common risk factors for re-bleeding in aneurysmal subarachnoid hemorrhage patients. Method: We reviewed all publications on the risk factors of the re-bleeding or rerupture of already bled intracranial aneurysms. This Meta analysis included studies published from the year 2000 until 2013. Pooled mean difference was calculated for the continuous variables (Age), and pooled odds ratio (OR) was calculated for categorical factors. Heterogeneity was tested first. If it is significant (p<0.05), random effect model was applied, otherwise, fixed model was used. Software - Review manager was used to find pooled effects and perform significant test for each potential risk factor. Results : We identified 174 articles. Only 7 retrospective studies had met the inclusion criteria, with 2470 patients, 283 patients had aneurysmal re-bleeding. The weighted average rate of re-bleeding is 11.3% with 95% confidence interval [CI]: 10.1-12.6. Statistically significant risk factor for re-bleeding were sex (OR 1.46; 95% CI: 1.11, 1.92), high systolic blood pressure [SBP] (OR 2.52; 95% CI: 1.40, 4.53), aneurysm size (OR 3.00; 95% CI: 2.06- 4.37), clinical condition (Hunt & Hess) (OR 4.94; 95% CI: 2.29, 10.68), and Fisher Grade (OR 2.29; 95% CI: 1.45, 3.61). Conclusion: Sex, high SBP, high Fisher Grade, aneurysm size larger than 10 mm, and patients with poor clinical condition (Hunt & Hess) were independent risk factors for aneurysmal re-bleeding. The importance of early aneurysm intervention should be emphasized to eliminate the risk of re-bleeding and poor outcome.