Effects of subarachnoid extension following intracerebral hemorrhage: A systematic review and meta-analysis

The effects of subarachnoid extension (SAHE) following intracerebral hemorrhage (ICH) have not yet been fully understood. We conducted a systematic review and meta-analysis of published literature on this topic to better understand the effects of SAHE. METHODS: PubMed, Embase, and Cochrane databases were thoroughly searched from inception to October 16, 2022 to identify studies that evaluated the association between SAHE and mortality and worse functional outcomes in primary ICH. Crude odds ratios (cOR) and adjusted odds ratios (aOR) with 95% confidence interval (CI) were calculated to compare the endpoints. RESULTS: Three studies with 3368 participants were eventually included in the analysis. In the short-term follow-up of the primary endpoint, no association was observed between SAHE and mortality (cOR: 0.51, 95% CI: 0.01–28.19; aOR: 2.31, 95% CI: 0.72–7.45). In the long-term follow-up of the primary endpoint, SAHE was associated with a significantly increased mortality of patients with primary ICH (cOR: 3.00, 95% CI: 2.27–3.98); however, only 1 study provided the values of aOR and 95% CI and showed that SAHE was not associated with increased mortality (aOR: 1.14, 95% CI: 0.71–1.83). For the secondary endpoint, the data of only 1 study on major disability (modified Rankin Scale = 3–5) were available, and the results revealed that SAHE increased the probability of major disability, but not after adjusting for baseline hematoma volume. CONCLUSION: There is insufficient evidence to demonstrate the correlation between SAHE and mortality and worse functional outcomes in primary ICH. The validation of this correlation requires further studies as the potential effect and mechanisms of SAHE remain unclear.