Stellate Ganglion Block in Subarachnoid Hemorrhage: A Promising Protective Measure Against Vasospasm?

BACKGROUND:Stellate ganglion block (SGB) may have protective effects in patients at risk of vasospasm following subarachnoid hemorrhage (SAH) due to reduced sympathetic activity. However, the safety and clinical outcomes of SGB in this scenario are not definitively known. The objective was to evaluate the safety, clinical outcomes, and cerebral blood flow velocity in patients submitted to SGB or cervical sympathectomy with SAH. METHODS:Following Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, a systematic review and meta-analysis of studies investigating SGB or cervical sympathectomy use in SAH were conducted. PubMed, Cochrane Library, and Embase were evaluated. Patients with mRS from 0 to 2, GOS from 4 to 5, or symptom resolution were considered favorable clinical outcomes. Related mortality was defined as death by vasospasm or delayed cerebral ischemia. RESULTS:The analysis included 8 studies comprising 182 patients. Only 2 studies employed SGB prophylactically. The results revealed favorable outcomes in 52% of patients (95% CI: 37%-65%). The overall incidence of complications was 2% (95% CI: 0% -26%). The mortality rate was 13% (95% CI: 7%-21%), with a vasospasm-related mortality rate of 11% (95% CI: 2%-20%). A decrease of cerebral blood flow velocity was reported in 4 studies. CONCLUSIONS:The notable reduction in cerebral blood flow velocity following SGB, alongside positive outcomes and a low occurrence of mortality and complications, highlights its significance as a therapeutic intervention for vasospasm following SAH. While the number of studies evaluating SGB as a preventive measure is limited, the promising results emphasize the importance of future research.