Background and purpose
To investigate the effect of locally applied nimodipine prolonged-release microparticles on angiographic vasospasm and secondary brain injury after experimental subarachnoid hemorrhage (SAH).
Conclusions
Local delivery of high-dose nimodipine prolonged-release microparticles at high concentration resulted in significant reduction in angiographic vasospasm after experimental SAH and with no histological signs for matrix toxicity.
Methods
70 male Wistar rats were categorized into three groups: 1) sham operated animals (control), 2) animals with SAH only (control) and the 3) treatment group. SAH was induced using the double hemorrhage model. The treatment group received different concentrations (20%, 30% or 40%) of nimodipine microparticles. Angiographic vasospasm was assessed 5 days later using digital subtraction angiography (DSA). Histological analysis of frozen sections was performed using H&E-staining as well as Iba1 and MAP2 immunohistochemistry.
Purpose
To investigate the effect of locally applied nimodipine prolonged-release microparticles on angiographic vasospasm and secondary brain injury after experimental subarachnoid hemorrhage (SAH).
Results
DSA images were sufficient for assessment in 42 animals. Severe angiographic vasospasm was present in group 2 (SAH only), as compared to the sham operated group (p<0.001). Only animals within group 3 and the highest nimodipine microparticles concentration (40%) as well as group 1 (sham) demonstrated the largest intracranial artery diameters. Variation in vessel calibers, however, did not result in differences in Iba-1 or MAP2 expression, i.e. in histological findings for secondary brain injury. Conclusions: Local delivery of high-dose nimodipine prolonged-release microparticles at high concentration resulted in significant reduction in angiographic vasospasm after experimental SAH and with no histological signs for matrix toxicity.