Ultrasound-guided suprafascial plane block for forearm AVF angioplasty: a motor-sparing, image-standardizable alternative to brachial plexus block in a single-center retrospective comparison

Background Balloon angioplasty for forearm arteriovenous fistula (AVF) often provokes substantial pain during inflation. Objective To compare an ultrasound-guided suprafascial plane block (SFPB) with brachial plexus block (BPB) during forearm AVF percutaneous transluminal angioplasty (PTA), focusing on analgesic effectiveness and safety. Methods Single-center, retrospective comparative study (January 1–December 31, 2025) of consecutive adults with forearm radiocephalic AVFs. SFPB targeted the superficial fascia–deep adipose tissue (SF–DAT) interface after sheath placement and guidewire traversal; BPB was completed before venipuncture. The primary endpoint was peak-inflation pain on the numeric rating scale (NRS, 0–10). Secondary outcomes included rescue analgesia, procedure time, block-related complications, and short-term patency. Results We analyzed SFPB (n=32) and BPB (n=35). The primary endpoint favored BPB (mean peak-inflation NRS 1.54 ± 0.74 vs 2.66 ± 0.85; mean difference −1.12, 95% CI −1.51 to −0.73; p =0.0038). Importantly, SFPB still met the prespecified adequacy threshold in most cases (NRS ≤3 in 87.5%, 28/32) without rescue or conversion and with no transient motor block, whereas BPB produced universal transient motor block and hoarseness in 2 patients. Procedure time did not differ significantly (70.77 ± 37.51 vs 87.49 ± 36.21 min; p =0.0613). One- and three-month primary patency was 100% in both groups. Conclusions SFPB provided clinically adequate, motor-sparing analgesia that is compatible with outpatient workflow, while BPB achieved lower NRS at the expense of motor involvement. These findings support SFPB as a pragmatic, image-standardizable alternative; prospective trials are warranted.