Cisterna Magna Injection Mouse Model of Subarachnoid Hemorrhage (SAH): A Systematic Literature Review of Preclinical SAH Research

Objective: This review article describes the characteristics of published literature using the cisterna magna blood injection mouse model of subarachnoid hemorrhage (SAH) with the aim to define particular standards and identify moderators of mortality rate, SAH grade, and large artery vasospasm. Methods: We searched for English-original peer-reviewed studies which reported the induction of SAH in mice via single or multiple blood injections into the cisterna magna. The search included studies published until 13th February 2023 on PubMed, Embase and Web of Science. Furthermore, we investigated the reporting of mortality rate, vasospasms by measuring large arteries, and SAH grade in cisterna magna blood injection mouse model. Results: Seven articles out of 136 identified records matched our inclusion criteria and were therefore included in descriptive analysis. Four articles reported the mortality rate which varied between zero and 22 percent. Five articles displayed vasospasms of large cerebral arteries including basilar artery (BA), anterior cerebral artery (ACA), and middle cerebral artery (MCA). Interestingly, the diameters of the observed arteries started to decrease already within the first hour after blood injection and achieved the lowest values at different times, but mainly between six and twelve hours after SAH induction. The artery diameters reached nearly their pre-SAH (control group) diameters approximately after four to seven days after SAH. However, the SAH severity grade was reported in none of these publications. No uniform model characteristics were observed in current literature. Conclusion: A systemic overview of the cisterna magna blood injection mouse model of SAH is presented. An important heterogeneity was observed. Hence, standardized model features and study endpoints have to be defined in order to improve reporting frequency and quality to enhance the reproducibility of preclinical SAH research in the future.