['Brachial plexus block offers several advantages when creating vascular access for hemodialysis. However, no controlled studies have directly evaluated arteriovenous fistula (AVF) blood flow in patients anesthetized by this method. We compared the effects of ultrasound-guided, infraclavicular brachial plexus block and local infiltration anesthesia on blood flow in the radial artery and AVF during the early and late postoperative periods.', 'Sixty patients were randomly assigned to an experimental group, which received infraclavicular brachial plexus block (IB), or to a control (C) group that received local infiltration anesthesia. Blood flow in the distal radial artery was measured before and after IB or infiltration anesthesia. AVF flow during the early and late postoperative period was evaluated using duplex ultrasound imaging. The rates of primary fistula failure were also compared.', 'After anesthesia, preoperative radial arterial flow was 56 ± 8.6 mL/min in group IB vs 40.7 ± 6.11 mL/min in group C (P < .0001). Blood flow in the fistula, measured in mL/min at 3 hours, 7 days, and 8 weeks postoperatively, was also greater in group 1B vs group C, respectively, at 69.6 ± 7.9 vs 44.8 ± 13.8 (P < .001), 210.6 ± 30.9 vs 129 ± 36.1 (P < .001), and 680.6 ± 96.7 vs 405.3 ± 76.2 (P < 0.001).'] Does ultrasound-guided infraclavicular brachial plexus block enhance postoperative blood flow in arteriovenous fistulas?