Stellate ganglion block for preserving arteriovenous fistula in hemodialysis patients undergoing major lower limb orthopedic surgeries: randomized control trial

Background Major lower limb orthopedic surgeries can lead to hemodynamic alterations and increase the risk of arteriovenous (AV)fistula thrombosis. This study assessed the role of stellate ganglion block (SGB) in preserving the AV fistulas in hemodialysis (HD)patients undergoing major lower limb orthopedic surgeries. Methods In this randomized, controlled, double-blind trial, 50 chronic renal failure patients (ASA physical status III, aged 21-75 years) scheduled for major lower limb orthopedic surgeries were randomized into two groups: Group S received an ultrasound-guided SGB before spinal anesthesia, while Group C received a sham procedure. AVF function was assessed using Doppler ultrasonography on postoperative days 1 and 7. Primary outcome was AVF flow rate. Secondary outcomes included peak systolic velocity (PSV), end-diastolic velocity (EDV), resistive index (RI), thrombosis rate, and functional failure. Results Group S demonstrated significantly higher AVF flow rates on both postoperative day 1 (276.96 +/- 49.66 ml/min vs. 217.44 +/- 46.73 ml/min) and day 7 (254.96 +/- 49.38 ml/min vs. 204.56 +/- 47.11 ml/min), with large effect sizes (Cohen's d = 1.23 and 1.04, respectively; p < 0.001). PSV and EDV were significantly improved, and RI was significantly lower in Group S. Thrombosis (8% vs. 36%) and failure rates (32% vs. 64%) were significantly reduced compared to the control group (p < 0.05). Conclusions Pre-emptive stellate ganglion block was associated with significantly improved AVF flow rate postoperatively and reduced thrombosis and functional failure, suggesting its clinical benefit in maintaining AVF patency during major surgeries in HD patients.