Ultrasound-guided Injection of the Levator Scapulae Muscle in a Cadaver Model

Abstract

Background: Despite the advantages of ultrasound and previous anatomical data on neuromuscular junction locations, to the best of our knowledge, the feasibility and accuracy of precise ultrasound-guided injection techniques into the proposed injection site of botulinum neurotoxin for the levator scapulae muscle have not been assessed in any publication. Objective: In the present cadaver-based study, the ultrasound-guided injection technique in the middle and distal portions of the levator scapulae muscle was evaluated to determine whether this method distributes injections properly to the target muscle in fresh cadavers. Study Design: Cadaveric study. Setting: A cadaver laboratory. Methods: Twenty fresh cadavers were used. Real-time B-mode ultrasound scanning was performed interfaced with a linear array transducer. A mixture of 0.5 mL of dye and yellow filler was injected transverse in-plane with a 6 cm 21-G. needle. Each specimen was dissected to determine whether the dye was correctly targeted to the middle and distal portions of the levator scapulae muscle and to evaluate the accuracy of the injections and any complications. Results: All 40 injections were successfully injected within the middle and distal portions of the levator scapulae muscle. When dissecting the cadavers, the dye spread was evenly distributed along the muscle fiber. Limitation: Despite successful injection into the middle and distal portions of the levator scapulae muscle, the usefulness of this technique was not verified in clinical practice. Conclusions: The ultrasound-guided injection technique presented in this study might facilitate precise visualization and localization of the levator scapulae muscle, thereby enhancing the effectiveness and safety of botulinum neurotoxin treatment in cervical dystonia.