Purpose: Delayed cerebral ischemia (DCI) still remains a major complication after subarachnoid hemorrhage (SAH). The aim of our study was to evaluate whether flow analysis of admission digital subtraction angiography (DSA) using parametric color coding (PCC), a postprocessing algorithm, allows ultra-early identification of SAH patients at risk for developing subsequent symptomatic vasospasm.
Methods: In this study 52 patients who suffered SAH from aneurysm rupture, were retrospectively enrolled. Of the patients 26 developed DCI and angiographically proven cerebral vasospasm and 26 age, gender-and clinical status-matched SAH patients without DCI served as controls. Using PCC, the following flow parameters were calculated: cerebral circulation time (CirT), cortical relative time to peak (rTTP) and microvascular transit time (TT).
Results: Mean cerebral CirT and cortical rTTP were longer in the DCI group (6.42 s ± 1.54 and 3.16 s ± 0.86, respectively) than in the non-DCI group (5.77 s ± 1.86 and 3.11 s ± 1.41, respectively), but without statistical significance. The mean microvascular TT was statistically significantly (p = 0.04) longer in the DCI group (3.19 s ± 0.78) than in the non-DCI group (2.67 s ± 0.73).
Conclusion: Angiographic flow analysis might be suitable for ultra-early detection and quantitative assessment of microcirculatory injury in SAH patients, predictive of developing subsequent DCI. Prolonged microvascular TT seems to be a significant independent factor positively associated with DCI development. Identifying SAH patients at risk for DCI ultra-early after ictus might contribute to initiate prophylactic therapies before clinical deterioration.
Keywords: Cerebral vasospasm; Delayed cerebral ischemia; Flow analysis; Image post-processing; Subarachnoidal hemorrhage.