Simple and efficient rat model for studying delayed cerebral ischemia after subarachnoid hemorrhage

Delayed cerebral ischemia (DCI) is a late phase of consequences of subarachnoid hemorrhage (SAH) that causes poor outcome and has become the focus of current research. The aim of this study was to characterize an experimental SAH technique for studying DCI after SAH.

A double injection SAH rat model with a tiny incision was introduced. At 7 days post-SAH induction, the diameter and luminal cross-sectional area (CSA) of the basilar artery (BA) were measured. In vivo fluorescence microscopy and magnetic resonance perfusion-weighted imaging (MRPWI) were used to evaluate the occurrence of DCI. Normal and sham-operated groups served as References RESULTS: Compared to the sham group, in SAH group, the diameter and CSA of the BA were decreased, and the CBF in the SAH group was also reduced to barely half of the level in the sham group. Moreover, both the proportion and severity of microarterial constrictions were increased significantly in the SAH group when compared to those in the sham group.

Complete exposure of the atlanto-occipital membrane is avoided, only a tiny region is exposed to identify the puncture spot. Lower mortality, reduced operative trauma and shorter procedure time are advantages to existing models. Multiple techniques for DCI assessment were used including in vivo microscopy and MRPWI.

The current study demonstrates that our SAH model was successfully established and may serve to help identify a novel target for the treatment of DCI after SAH.