The efficacy of ultrasound-guided selective cutaneous nerve block during percutaneous transluminal angioplasty for radiocephalic arteriovenous fistulas.

Background: Percutaneous transluminal angioplasty (PTA) for dysfunctional radial cephalic arteriovenous fistulas (RC-AVF) is associated with severe pain. This study evaluates the effectiveness of ultrasound-guided selective cutaneous nerve block (SCNB) in reducing procedural pain.

Methods: A total of 292 dialysis patients with RC-AVFs undergoing 292 PTA procedures were retrospectively reviewed. Patients were categorized into three groups based on the anesthesia method: infiltration anesthesia (IA, n = 50), ultrasound-guided infiltration anesthesia (USIA, n = 74), and USIA combined with SCNB (USIA + SCNB, n = 168). SCNB targeted the lateral antebrachial cutaneous nerve (LACN) in all cases, with additional superficial radial nerve (SRN) blocks performed in 106 cases at the operator's discretion. Ultrasound imaging with an 18 MHz linear probe was used to visualize nerves and veins, and 1% lidocaine was administered using a 25G 25 mm needle. Pain was assessed using the Numerical Rating Scale (NRS).

Results: No significant differences in baseline characteristics were observed among the IA, USIA, and USIA + SCNB groups. The mean NRS pain scores during balloon inflation were significantly lower in the USIA + SCNB group (2.33 ± 2.08) compared to the IA group (5.24 ± 2.34, p < 0.001) and the USIA group (4.14 ± 2.70, p < 0.001). Among 38 cases with isolated forearm lesions, there was no significant difference between LACN-only and LACN + SRN blocks (2.42 ± 2.04 vs 2.63 ± 1.92, p = n.s.). However, in 75 cases with isolated peri-anastomotic lesions, the addition of an SRN block significantly reduced pain compared to LACN block alone (1.77 ± 1.82 vs 3.00 ± 1.78, p < 0.05).

Conclusion: SCNB, particularly LACN block for forearm stenosis and combined LACN + SRN block for peri-anastomotic lesions, effectively reduces pain during PTA of RC-AVFs. When combined with USIA, SCNB further enhances analgesic effectiveness during PTA, and the two methods demonstrate a synergistic effect. This method provides safe, motor-sparing anesthesia, improving patient comfort in endovascular procedures.