Stellate Ganglion Block Therapy for Complex Regional Pain Syndrome: A Systematic Review and Meta-Analysis

Background: Sympathetic ganglion block (SGB) technique is becoming increasingly prevalent in the treatment of complex regional pain syndromes (CRPS). Given the varied reported effectiveness of these techniques and the heterogeneity of treatment regimens, there is an urgent need for consistent and high-quality evidence on the efficacy and safety of such procedures. Objectives: This study aimed to compare the efficacy of SGB therapy for CRPS-related pain. Study Design: A meta-analysis of randomized controlled trials (RCTs). Methods: PubMed, EMBASE, Web of Science, CINAHL, US National Institutes of Health Clinical Trials Registry, Google Scholar, and Cochrane Library Databases were systematically searched between January 1967 and April 2023. A meta-analysis of the included RCTs on SGB was conducted to evaluate the effectiveness and risk of bias (ROBs) of SGB. Results: After screening 8523 records, 12 RCTs were included in this meta-analysis. Compared with controls, the visual analog pain score decreased by a weighted mean difference (WMD) of-6.24 mm (95% CI, -11.45, -1.03; P = 0.019) in the random-effects model, and the numerical scale score was reduced by a WMD of -1.17 mm (95% CI, -2.42, 0.08; P = 0.067) in the fixedeffects model, indicating a pain relief. The methodological quality of the included RCTs was high, with an average PEDro score of 7.0 (range: 5-9). Limitations: The number of included trials was limited. Conclusions: SGB therapy can reduce pain intensity in patients with CRPS with few adverse events. However, owing to the relatively high heterogeneity of the included RCTs, a larger sample of high-quality RCTs is needed to further confirm this conclusion.