Double-bend needle modification for transthyrohyoid vocal fold injection.

Abstract

Our objective was to describe an injection needle modification for awake in-office vocal fold injections through a percutaneous transthyrohyoid approach. Two separate 45° angle bends are created at the hub and 1 cm from the needle tip of a 25-gauge, 1.5-inch needle. After adequate endolaryngeal anesthesia, the needle is passed via the thyrohyoid membrane into the airway. The needle tip is at a 90° angle to the syringe, providing access to the entire vocal fold surface, regardless of chin position or thyroid cartilage angulation. The bend at 1 cm also serves as a marker to measure the depth of the needle within the soft tissue. The double-bend needle modification allows for complete access to the entire length of the true vocal fold in one pass as well as a marker to measure depth of the needle in the tissue. Limitations may include bleeding from the injection site, insufficient needle length in patients with a long anterior-posterior dimension of the larynx, and potential difficulty passing a needle through a calcified thyrohyoid membrane.