Efficacy and Safety of Ultrasound-Guided Nerve Block Versus Local Anesthesia for Arteriovenous Fistula Angioplasty: A Systematic Review and Meta-Analysis.

BACKGROUND AND AIMS: Severe intra-procedural pain commonly complicates percutaneous transluminal angioplasty (PTA) for dysfunctional arteriovenous fistulas (AVFs), undermining patient cooperation and potentially increasing the need for sedative medications. This systematic review and meta-analysis aimed to evaluate the analgesic efficacy, safety, and clinical performance of ultrasound-guided nerve block (UGNB) versus local anesthesia (LA) in adult patients undergoing AVF PTA. METHODS: We searched PubMed, Embase, Scopus, the Cochrane Library, and Web of Science for eligible randomized controlled trials and cohort studies published up to September 1, 2025. The primary outcome was intra-procedural pain rated using VAS or NRS on a 0-10 scale. The secondary outcome was overall safety, assessed using the available complication-free outcome. Random-effects models were used for pooled analyses. Heterogeneity was explored using Galbraith plots and leave-one-out analyses. Funnel plots were generated for exploratory visualization because fewer than 10 studies were included. Subgroup analyses were performed according to UGNB subtype, and an exploratory subgroup analysis was additionally conducted by study design. RESULTS: Four eligible studies, including 664 participants from East Asia, were included in the quantitative synthesis. In the primary pain analysis, UGNB was associated with a marked reduction in intra-procedural pain relative to LA (SMD -2.85, 95% CI -4.70 to -1.01; p < 0.001), although heterogeneity remained extreme (I 2 = 98.45%). Galbraith and leave-one-out analyses identified Wen et al. as the most influential study; however, the direction and statistical significance of the pooled effect remained unchanged after omitting any single study. Subgroup analysis by block type showed a significant analgesic effect for BPB, whereas the SCNB subgroup had a wide confidence interval and very high heterogeneity; no significant between-subgroup difference was detected. The pooled log risk ratio for the complication-free outcome was -0.02 (95% CI -0.05 to 0.02; p = 0.27), indicating no clinically meaningful difference in overall safety between groups. No major nerve injury, pneumothorax, or persistent motor deficits were reported. CONCLUSION: UGNB was associated with superior analgesia without a clear increase in adverse events during AVF PTA. Current evidence does not establish a statistically significant difference between BPB and SCNB, and the SCNB subgroup should be interpreted cautiously because of substantial heterogeneity. Larger multicenter trials are needed to compare block techniques directly and to evaluate recovery, patency, and cost-effectiveness.