Enhanced visual acuity with echogenic needles in ultrasound-guided axillary brachial plexus block: a randomized, comparative, observer-blinded study.

Background: We prospectively evaluated the effect of insertion angle on the visibility of echogenic and nonechogenic needles in phantoms and in axillary nerve blocks in patients.

Methods: Conventional and echogenic needles were studied in phantoms at insertion angles of 0-30°, 30-45°, and ≥ 45°. Operators rated comfort and image quality during the procedure and experts blinded to the needle groups randomly analyzed videos for tip and shaft visibility, surrounding tissue visibility, sharpness of the needle surface, and percentage of time with the needle completely visible.