Ultra-early angiographic vasospasm after aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis

Objective: After aneurysmal subarachnoid hemorrhage (aSAH), prognosis is affected heavily by the presence of delayed cerebral ischemia (DCI). There is growing recognition of ultra-early angiographic vasospasm (UEAV) occurring within 48 hours of aSAH; however, its relationship with DCI and ultimately prognosis remains unclear. Methods: Various databases limited to the English language through September 2016 were searched systematically. Eligible studies were those comparing UEAV with control non-UEAV outcomes and follow-up. Two independent reviewers evaluated the quality of studies and abstracted the data, with discrepancies resolved by a third. We calculated odds ratios (ORs) and 95% confidence intervals for all outcomes by using random-effects meta-analyses and performed a heterogeneity analysis. Results: Four comparative studies were selected for analysis. Pooled analysis demonstrated that UEAV compared with no-UEAV was associated with greater proportion of rupture aneurysms sized greater than 12 mm (38.3% vs. 24.3%, P < 0.00001). A significantly greater number of patients with UEAV had ruptured MCA aneurysms compared with patients without UEAV (29.7% vs. 19.9%, P = 0.005). Compared with no-UEAV, patients with UEAV were significantly associated with symptomatic cerebral vasospasm (OR 2.07, P = 0.05) and DCI/infarction (OR 2.52, P = 0.02). A significant association also was found between UEAV and an unfavorable outcome at follow-up (OR 1.64, P = 0.03) and greater mortality (OR 2.65, P < 0.00001). Conclusions: UEAV was significantly associated with symptomatic cerebral vasospasm, DCI/infarction, unfavorable outcome at follow-up, and greater mortality. Patients with intracerebral hematoma, intraventricular hemorrhage (Fisher Grade IV), larger ruptured aneurysms >12 mm, and an MCA location were more likely to have UEAV.