Repeat digital subtraction angiography after a negative baseline assessment in nonperimesencephalic subarachnoid hemorrhage: a pooled data meta-analysis

Object. A repeat digital subtraction angiography (DSA) study of the cranial vasculature is routinely performed in patients with diffuse nonperimesencephalic subarachnoid hemorrhage (SAH) after negative baseline CT angiography (CTA) and DSA studies. However, DSA carries a low but substantial risk of neurological complications. Therefore, the authors evaluated the added value of repeat DSA in patients with initial angiographically negative diffuse nonperimesencephalic SAH. Methods. A systematic review of the contemporary literature was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. Studies from January 2000 onward were reviewed since imaging modalities have much improved over the last decade. A pooled analysis was conducted to identify the detection rate of repeat DSA. In addition, the diagnostic yield of repeat DSAs in a prospectively maintained single-center series of 1051 consecutive patients with SAH was added to the analysis. Results. An initial search of the literature yielded 179 studies, 8 of which met the selection criteria. Another 45 patients from the authors' institution were included in the study, providing 368 patients eligible for the pooled analysis. In 37 patients (10.0%, 95% CI 7.4%-13.6%) an aneurysm was detected on repeat DSA. The timing of the repeat DSA varied from 1 to 6 weeks after the initial DSA. The use of 3D techniques was poorly described among these studies, and no direct comparisons between CTA and DSA were made. Conclusions. Repeat DSA is still warranted in patients with a diffuse nonperimesencephalic SAH and negative initial assessment. However, the exact timing of the repeat DSA is subject to debate.