Abstract: Objective  To observe the effects of different anastomotic angles (30° vs. 45°) between radial artery and cephalic vein on early postoperative brachial artery blood flow in autogenous arteriovenous fistulas (AVFs).  Methods  A prospective, randomized and controlled trial was conducted for patients with end-stage renal disease (ESRD) undergoing first AVF creation at the Department of Nephrology, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine from October 2022 to December 2024. The participants were randomized into two groups using a random number table: group 1 (30° anastomotic angle) and group 2 (45° anastomotic angle). After the surgery for 4 and 8 weeks, color Doppler ultrasound was used to measure internal diameter of the proximal inflow radial artery, peak systolic velocity (PSV) of the proximal inflow radial artery, blood flow, internal diameter and peak velocity of the brachial artery, and the anastomotic diameter. These parameters were compared between the two groups.  Results  After the surgery for 4 and 8 weeks, no statistically significant differences were observed between the two groups in: proximal inflow radial artery diameter (4 weeks: 3.49±0.83 mm vs. 3.27±0.70 mm, t=0.554, P=0.294; 8 weeks: 3.89±0.30 mm vs. 3.93±0.90 mm, t=-0.086, P=0.466), radial artery PSV [4 weeks: 99.00 (89.00, 104.25) cm/s vs. 99.00 (89.15, 101.75) cm/s, Z=-0.845, P=0.412; 8 weeks: 110.31±18.12 cm/s vs. 113.56±20.01 cm/s, t=-0.340, P=0.369), brachial artery blood flow (4 weeks: 681.75±251.35 mL/min vs. 593.63±198.85 mL/min, t=-0.778, P=0.450; 8 weeks: 752±161.74 mL/min vs. 827.38±350.04 mL/min, t=-0.553, P=0.296), brachial artery diameter [4 weeks: 4.80 (4.55, 5.05) mm vs. 5.40 (4.58, 6.00) mm, Z=-0.956, P= 0.339; 8 weeks: 4.85±0.47 mm vs. 5.33±0.70 mm, t=-1.579, P=0.066], brachial artery peak velocity (4 weeks: 125.03±26.51 cm/s vs. 112.54±15.23 cm/s, t=1.155, P=0.272; 8 weeks: 127.99±23.78 cm/s vs. 123.21±21.18 cm/s, t=0.424, P=0.339), anastomotic diameter [4 weeks: 4.00 (3.93, 4.00) mm vs. 4.00 (3.33, 4.00) mm, Z=-0.785, P=0.432; 8 weeks: 4.00 (4.00, 4.18) mm vs. 4.00 (3.73, 4.00) mm, Z=-1.574, P=0.115].   Conclusion  In radial artery-cephalic vein AVF creation, 30° and 45° anastomotic angles had no significant difference in early postoperative brachial artery blood flow. To increase the postoperative brachial artery flow, the factors of vascular condition, surgical technique, suture method, and postoperative management must be comprehensively considered.

Key words: Arteriovenous fistula, Anastomotic angle, Brachial artery blood flow, Hemodialysis