Early Stellate Ganglion Block May Prevent Vasospasm in Aneurysmal Subarachnoid Hemorrhage

Introduction Stellate Ganglion Blockade (SGB) has shown promising results as a rescue therapy for refractory cerebral vasospasm (CVS) caused by aneurysmal subarachnoid hemorrhage (aSAH). It works by inhibiting cervical sympathetic stimulation, decreasing vasoconstriction in cerebral vessels, and improving blood flow. However, its role in preventing CVS and subsequent delayed cerebral ischemia (DCI) when used in the early stages of SAH is still inadequately characterized. As part of our efforts to address this issue, we conducted this review to summarize the latest evidence on the effectiveness of early SGB use in preventing CVS, and in turn, reducing the risk of DCI following aSAH. Methods A systematic search was carried out in PubMed/MEDLINE using a predefined search criterion for relevant literature from inception to July 2025. Two authors independently performed a database search, data collection, and study quality evaluation. The study's primary outcomes were the incidence of vasospasm and/or delayed cerebral ischemia. Results This review included data from 15 studies with more than 350 patients from 8 countries. Overall, more than half of the patients treated with SGB experienced subsequent clinical improvement compared to the control group (RR: 0.52; 95% CI: 0.37‐0.65; p <0.01). Interestingly, early ganglion block proved to be effective in preventing CVS and DCI in SAH patients. 36% of patients in the SGB group developed CVS on TCD compared to 70% in the control group (RR: 0.51, 95% CI: 0.31‐0.89; P<0.010). Additionally, only 16% of the patients went on to develop DCI in the early SGB group compared to 30% in the control group, which is a nearly 50% decrease in the incidence of this dangerous complication. Lastly, the SGB group also had more asymptomatic survivors (mRS score 0) evaluated at 90 days (66% vs 43%; RR: 1.69, 95% CI 0.94‐3.12). Conclusion SGB is an easy and practical intervention that has the potential to effectively reduce the risk of CVS and subsequent DCI, a common yet terrifying complication of SAH. Unfortunately, reliable interventions to identify high‐risk patients for developing DCI are still inadequately characterized. Hence, we hope this study becomes a platform for larger multicenter studies, especially in the United States, for early prediction of potential vasospasm and developing precise interventions to prevent them.